JP7031125B2 - Optical Waveguide, Optical Waveguide Connectivity and Electronic Devices - Google Patents

Description

The present invention relates to an optical waveguide, an optical waveguide connector and an electronic device.

When optically connecting a silicon substrate on which an optical waveguide is formed and optical wiring such as an optical fiber, a method of interposing an optical waveguide between them is known. By interposing the optical waveguide, the optical input / output points on the silicon substrate can be guided by the optical waveguide, so that the optical connection between the functional element and the optical wiring can be easily performed.

For example, in Patent Document 1, exuded light (evanescent light) is captured and optically connected between a polymer waveguide array formed on a polymer and a silicon waveguide array formed on a silicon chip. Structures that are optically connected by an adivatic bond are disclosed. Further, Patent Document 1 discloses that by combining a convex portion formed on a polymer and a concave portion formed on a silicon chip, both are self-aligned. As a result, the polymer waveguide array and the silicon waveguide array can be accurately aligned, so that the loss generated in the adiabatic coupling can be suppressed.

Japanese Unexamined Patent Publication No. 2014-81586

On the other hand, when the polymer waveguide array and the silicon waveguide array are optically connected, it is necessary to strongly press the silicon waveguide array against the polymer waveguide array. Therefore, since stress is concentrated inside the polymer waveguide array, there is a concern that the optical transmission efficiency of the polymer waveguide will decrease, and as a result, the optical coupling efficiency will decrease.

An object of the present invention is an optical waveguide capable of achieving good optical coupling efficiency with other optical components, and the optical waveguide and other optical components are connected with good optical coupling efficiency with high reliability. It is an object of the present invention to provide a highly reliable electronic device including an optical waveguide connector and such an optical waveguide connector.

Such an object is achieved by the present invention of the following (1) to (10).
(1) A core layer including a core portion and a side surface clad portion adjacent to the side surface of the core portion, and having a first main surface and a second main surface which are in a front-to-back relationship with each other.
The first clad layer laminated on the first main surface and
Have,
The core layer is made of a resin material and is made of a resin material.
The base polymer of the core portion and the base polymer of the side clad portion are the same.
The second main surface is an optical coupling surface that includes a clad-corresponding portion corresponding to the side surface clad portion and a core-corresponding portion corresponding to the core portion, and the core-corresponding portion is coupled to another optical component. ,
The clad-corresponding portion protrudes from the core-corresponding portion in the thickness direction of the core layer.
An optical waveguide characterized in that L2 / t is 0.01 to 20% when the protruding length of the clad-corresponding portion is L2 and the thickness of the core portion is t.

(2) The optical waveguide according to (1) above , wherein the coupling between the other optical component and the optical coupling surface is an adibatic coupling .

(3) Further, it has a second clad layer laminated on the second main surface.
The optical waveguide according to (1) or (2) above , wherein the end face of the second clad layer is recessed from the end face of the core portion .

(4) The optical waveguide according to (3) above, wherein the receding length L1 of the end face of the second clad layer is 10 to 10000 when the average width of the core portion is 1.

(5) The optical waveguide according to (4) above , wherein the portion of the second main surface on which the second clad layer is not laminated is exposed.

(6) The optical waveguide according to any one of (1) to (5) above, wherein the refractive index distribution of the core layer is a distribution in which the refractive index continuously changes in the width direction of the core portion.

(7) The optical waveguide according to any one of (1) to (6) above, further having a support layer laminated on the side opposite to the core layer of the first clad layer.

(8) The optical waveguide according to any one of (1) to (7) above, wherein the waveguide mode of the core portion is a single mode.

(9) The optical waveguide according to any one of (1) to (8) above,
Optical components optically connected to the optical waveguide,
An optical waveguide connector characterized by having.

(10) An electronic device including the optical waveguide connector according to (9 ) above.

According to the present invention, an optical waveguide capable of achieving good optical coupling efficiency with other optical components can be obtained.

Further, according to the present invention, a highly reliable optical waveguide connector in which the optical waveguide and other optical components are connected with good optical coupling efficiency can be obtained.

Further, according to the present invention, a highly reliable electronic device provided with the above-mentioned optical waveguide connector can be obtained.

It is a perspective view which shows the embodiment of the optical waveguide connection body of this invention. It is a perspective view which shows the state of connecting the optical waveguide connector shown in FIG. 1 and an optical fiber. It is a vertical sectional view of the optical waveguide connector shown in FIG. FIG. 3 is a partially enlarged view of the optical waveguide connector shown in FIG. It is a top view of the upper surface of the optical waveguide included in the optical waveguide connector shown in FIG. It is a vertical cross-sectional view which shows the state of manufacturing the optical waveguide connector shown in FIG. FIG. 3 is a vertical cross-sectional view showing the optical waveguide connector shown in FIG. It is a vertical sectional view which shows the modification of the optical waveguide connector shown in FIG. 7.

Hereinafter, the optical waveguide, the optical waveguide connector, and the electronic device of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

<Optical Waveguide Connection>
First, an embodiment of the optical waveguide connector of the present invention will be described.

FIG. 1 is a perspective view showing an embodiment of the optical waveguide connector of the present invention, FIG. 2 is a perspective view showing how the optical waveguide connector shown in FIG. 1 is connected to an optical fiber, and FIG. 3 is a perspective view. It is a vertical cross-sectional view of the optical waveguide connection shown in FIG. 1, and FIG. 4 is a partially enlarged view of the optical waveguide connection shown in FIG. In the following description, for convenience of explanation, the upper part of FIGS. 3 and 4 will be referred to as “upper” and the lower part will be referred to as “lower”.

The optical waveguide connection 10 shown in FIG. 1 includes an optical waveguide 1 (the embodiment of the optical waveguide of the present invention), an optical connector 5 provided at an end of the optical waveguide 1, and an optical interposer 2 (optical component). , And a mounting board 3.

The optical waveguide 1 shown in FIG. 1 is long and has a sheet shape. In this optical waveguide 1, an optical signal can be transmitted between one end and the other end in the longitudinal direction.

As shown in FIG. 4, such an optical waveguide 1 includes a laminate in which the first clad layer 11, the core layer 13, and the second clad layer 12 are laminated in this order from the bottom. In the present specification, of the two main surfaces of the core layer 13 in FIGS. Second main aspect) ".

Further, FIG. 5 is a plan view of the upper surface of the optical waveguide included in the optical waveguide connection shown in FIG. As shown in FIG. 5, the core layer 13 includes eight long core portions 14 provided in parallel and side clad portions 15 adjacent to the side surfaces of each core portion 14. .. The core portion 14 is surrounded by a clad portion (side clad portion 15, first clad layer 11 and second clad layer 12), and light can be confined and propagated in the core portion 14. That is, these core portions 14 function as transmission paths for transmitting optical signals in the optical waveguide 1. The right end surface 102 of each core portion 14 serves as an optical input / output surface for inputting / outputting an optical signal at the right end of the optical waveguide 1 when the optical fiber 9 or the like shown in FIG. 2 is connected.

On the other hand, the second clad layer 12 is not laminated on the portion of the upper surface 104 of the core layer 13 near the left end surface 101 (hereinafter, this portion is referred to as “upper left surface 105”). The optical interposer 2 is provided so as to be in contact with the upper left surface 105. As a result, an adibatic bond is formed between the core portion 14 and the optical interposer 2 on the upper left surface 105. This adibatic bond means that it is optically connected via exuding light (evanescent light). As a result, optical signals can be mutually transmitted between the optical waveguide 1 and the optical interposer 2.

Therefore, the optical waveguide connecting body 10 has an optical waveguide 1 and an optical interposer 2 optically connected to the optical waveguide 1.

Then, in the optical waveguide 1 according to the present embodiment, as will be described in detail later, the portion of the upper surface 104 of the core layer 13 corresponding to the side surface clad portion 15 protrudes from the portion corresponding to the core portion 14. .. As a result, the decrease in the optical transmission efficiency of the core portion 14 due to the connection between the optical waveguide 1 and the optical interposer 2 is suppressed, and as a result, the optical coupling efficiency between the optical waveguide 1 and the optical interposer 2 can be further enhanced. can. As a result, a highly reliable optical waveguide connection 10 can be obtained.

Hereinafter, the optical waveguide connecting body 10 will be described in more detail.
(Optical waveguide)
FIG. 6 is a vertical cross-sectional view showing a state in which the optical waveguide shown in FIG. 4 and an optical interposer (optical component) are laminated to form an optical waveguide connection. Further, FIG. 7 is a vertical cross-sectional view showing the optical waveguide connection shown in FIG. In FIGS. 6 and 7, for convenience of explanation, only one core portion 14 and the two side surface clad portions 15 associated therewith are partially shown among the eight core portions 14 shown in FIG. The other core portions 14 and side clad portions 15 are not shown.

As described above, the core portion 14 is surrounded by the clad portion (side clad portion 15, the first clad layer 11 and the second clad layer 12), and light can be confined and propagated in the core portion 14.

The refractive index distribution in the cross section of the core layer 13 may be any distribution. This refractive index distribution may be a so-called step index (SI) type distribution in which the refractive index changes discontinuously, but at least the so-called graded distribution in which the refractive index in the width direction of the core portion 14 continuously changes. An index (GI) type distribution is preferred. As a result, even if there is some manufacturing variation, it is less likely to affect the optical coupling loss, so that the optical transmission efficiency of the core portion 14 is improved regardless of the manufacturing conditions, and the optical coupling between the optical waveguide 1 and the optical interposer 2 is improved. Efficiency is improved.

Further, the optical waveguide 1 and the core portion 14 formed therein may be linear or curved in a plan view, respectively. Further, the optical waveguide 1 and the core portion 14 formed therein may be branched or intersect in the middle of each.

The cross-sectional shape of the core portion 14 is not particularly limited, and may be, for example, a circle such as a perfect circle, an ellipse, or an oval, or a polygon such as a triangle, a quadrangle, a pentagon, or a hexagon. The rectangular shape) has an advantage that the core portion 14 can be easily formed.

On the other hand, the waveguide mode of the core portion 14 may be a multi-mode, but is preferably a single mode. As a result, it is possible to bond with high efficiency by adibatic bonding using evanescent light. Further, an optical waveguide 1 capable of optical connection with good optical coupling efficiency to an optical component whose waveguide mode is a single mode can be obtained.

The width and height of the core portion 14 (thickness of the core layer 13) are not particularly limited, but are preferably about 1 to 15 μm, more preferably about 2 to 12 μm, and more preferably about 3 to 10 μm. It is more preferable to have it. As a result, it is possible to suppress a decrease in transmission efficiency. Further, by setting the width and height of the core portion 14 within the above range, it becomes easy to set the waveguide mode of the core portion 14 to the single mode.

Further, as shown in FIG. 5, when a plurality of core portions 14 are arranged in parallel, the width of the side clad portions 15 located between the core portions 14 is not particularly limited, but is about 0.5 to 250 μm. It is preferably about 1 to 200 μm, more preferably about 2 to 125 μm, and even more preferably about 2 to 125 μm. As a result, it is possible to narrow the pitch of the core portions 14 while preventing the optical signals from being mixed (crosstalk) between the core portions 14.

On the other hand, the difference in refractive index between the core portion 14 and the clad portion (side clad portion 15, first clad layer 11 and second clad layer 12) is not particularly limited, but is about 0.001 to 0.05. It is preferably about 0.002 to 0.02, more preferably about 0.003 to 0.01. As a result, the transmission efficiency of the core portion 14 can be sufficiently increased, and a highly reliable optical waveguide connection body 10 can be obtained. That is, it is possible to reduce the power consumption, speed, and size of the optical waveguide connection body 10. Further, by setting the refractive index difference within the above range, it becomes easy to set the waveguide mode of the core portion 14 to the single mode.

The number of core portions 14 formed in the optical waveguide 1 is not particularly limited, but is preferably about 1 to 100. If the number of core portions 14 is large, the optical waveguide 1 may be multi-layered, if necessary. Specifically, the core layer and the clad layer can be layered alternately on the second clad layer 12 shown in FIG.

Examples of the constituent material (main material) of the core layer 13 as described above include acrylic resin, methacrylic resin, polycarbonate, polystyrene, cyclic ether resin such as epoxy resin and oxetane resin, polyamide, and polyimide. Polybenzoxazole, polysilane, polysilazane, silicone resin, fluororesin, polyurethane, polyolefin resin, polybutadiene, polyisoprene, polychloroprene, polyester such as PET and PBT, polyethylene succinate, polysulfone, polyether, benzocyclobutene. Examples thereof include various resin materials using components such as cyclic olefin resins such as based resins and norbornene resins as base polymers, as well as various glass materials such as quartz glass and borosilicate glass. The resin material may be a composite material or a polymer alloy in which materials having different compositions are combined.

Further, as the constituent material of the first clad layer 11 and the second clad layer 12, for example, the same material as the constituent material of the core layer 13 described above can be used, but in particular, (meth) acrylic resin and epoxy-based. It is preferably at least one selected from the group consisting of resins, silicone-based resins, polyimide-based resins, fluororesins, and polyolefin-based resins.

The optical waveguide 1 is preferably made of a resin material. As a result, the optical waveguide 1 becomes inexpensive, highly flexible and lightweight, and facilitates handling and mounting work.

Further, the optical waveguide 1 shown in FIG. 4 includes a cover layer 17 laminated on the upper surface of the second clad layer 12.

Examples of the constituent material of the cover layer 17 include polyethylene terephthalate (PET), polyethylene, various resin materials such as polyolefin such as polypropylene, polyimide and polyamide, and various glass materials such as quartz glass and borosilicate glass. ..

The average thickness of the cover layer 17 is not particularly limited, but is preferably about 5 to 500 μm, and more preferably about 10 to 400 μm. As a result, the cover layer 17 has an appropriate rigidity, so that the core layer 13 can be reliably supported and the core layer 13 and the second clad layer 12 can be reliably protected from external forces and the external environment. ..
The cover layer 17 may be provided as needed and may be omitted.

On the other hand, the optical waveguide 1 shown in FIG. 4 includes a support layer 16 laminated on the lower surface (opposite side of the core layer 13) of the first clad layer 11. As a result, the core layer 13 is reinforced by the support layer 16, so that a highly reliable optical waveguide 1 can be obtained.

The constituent material of the support layer 16 is not particularly limited, but can be selected from those listed as the constituent materials of the cover layer 17.

The average thickness of the support layer 16 is not particularly limited, but is preferably about 10 to 3000 μm, and more preferably about 20 to 1500 μm. As a result, the above-mentioned function of the support layer 16 is fully exhibited while preventing the optical waveguide 1 from becoming too thick.
The support layer 16 may be provided as needed and may be omitted.

Further, any layer may be interposed between the support layer 16 and the first clad layer 11 and between the cover layer 17 and the second clad layer 12, respectively, if necessary.

On the other hand, the second clad layer 12 laminated on the upper surface 104 of the core layer 13 does not necessarily have to be provided and may be omitted. However, by providing the second clad layer 12 as shown in FIG. 4, for example, when the optical waveguide 1 is connected to an optical fiber, the coupling efficiency with the optical fiber is improved, and the core portion 14 is exposed to an external force or an external environment. Can be protected. Therefore, the reliability of the optical waveguide 1 can be further improved.

Further, in the optical waveguide 1 shown in FIG. 4, as described above, the second clad layer 12 is not laminated on the upper left surface 105 of the upper surface 104 of the core layer 13. That is, in the optical waveguide 1 shown in FIG. 4, the left end surface 121 of the second clad layer 12 recedes to the right side of the left end surface 101 of the core layer 13. Due to the retreat of the second clad layer 12, when the optical interposer 2 is arranged with respect to the optical waveguide 1, interference between the second clad layer 12 and the optical interposer 2 can be avoided. Therefore, it becomes easy to arrange the optical waveguide 1 and the optical interposer 2, and the optical waveguide 1 and the optical interposer 2 are connected to each other while the core portion 14 is reliably protected by the second clad layer 12 except for the upper left surface 105. It can enhance the sex.

Further, since the core portion 14 is also exposed by exposing the upper surface 104 of the core layer 13, the distance between the core portion 14 and the optical interposer 2 can be shortened. This makes it possible to further increase the optical coupling efficiency between the two.

The length L1 of the upper left surface 105 in the longitudinal direction of the core portion 14 (see FIG. 5), that is, the length L1 (retracted length L1) in which the left end surface 121 of the second clad layer 12 is retracted is obtained. It is appropriately set according to the optical coupling efficiency to be obtained, but is optimized according to, for example, the width of the core portion 14. Specifically, when the average width of the core portion 14 is 1, the receding length L1 is preferably about 10 to 10000, and more preferably about 50 to 5000. By setting the receding length L1 within the above range, it is possible to sufficiently secure high optical coupling efficiency while avoiding an increase in the size of the optical waveguide connection body 10.

Here, of the upper surface 104 of the core layer 13, the portion 1045 corresponding to the side clad portion 15 is directed upward from the portion 1044 corresponding to the core portion 14 (with the lower surface 103), as shown in FIGS. Is protruding toward the other side). As a result, even if the optical interposer 2 is strongly pressed against the optical waveguide 1, the optical interposer 2 can be preferentially received by the portion 1045, so that stress concentration on the core portion 14 can be suppressed. Can be done. As a result, the decrease in the optical transmission efficiency in the optical waveguide 1 is suppressed, and as a result, the decrease in the optical coupling efficiency between the optical waveguide 1 and the optical interposer 2 is suppressed. That is, an optical waveguide 1 capable of achieving good optical coupling efficiency with other optical components can be obtained.

The portion 1045 and the optical interposer 2 may be merely in contact with each other, or may be fixed via an adhesive or the like.

The protruding length L2 (see FIG. 6) of the portion 1045 corresponding to the side clad portion 15 is appropriately set according to the thickness t of the core portion 14, but L2 / t is about 0.01 to 20%. It is preferably about 0.05 to 10%, more preferably about 0.1 to 5%, and even more preferably about 0.1 to 5%. By setting L2 / t within the above range, it is possible to suppress the concentration of large stress in the core portion 14 even when the optical interposer 2 is strongly pressed against the optical waveguide 1. At the same time, it is possible to prevent the distance between the core portion 14 and the optical interposer 2 from becoming too large. Both of these can suppress a decrease in the optical coupling efficiency between the optical waveguide 1 and the optical interposer 2.

When L2 / t is below the lower limit, the effect that the portion 1045 corresponding to the side clad portion 15 protrudes depending on the magnitude of the load applied to the optical interposer 2, that is, a large stress in the core portion 14. There is a risk that the effect of suppressing the concentration of light will be hardly obtained. On the other hand, if L2 / t exceeds the upper limit value, the separation distance between the core portion 14 and the optical interposer 2 may become too large depending on the thickness t of the core portion 14, and the optical coupling efficiency may decrease. ..

Further, of the upper surface 104 of the core layer 13, the portion 1045 corresponding to the side clad portion 15 protrudes, so that a gap is formed between the core portion 14 and the optical interposer 2. This gap may be a cavity in which nothing is provided, but inclusions such as an adhesive may be provided in the gap.

In the optical waveguide connection body 10 shown in FIGS. 6 and 7, an adhesive layer 6 is provided between the core portion 14 and the optical interposer 2. The optical waveguide 1 and the optical interposer 2 can be fixed to each other via the adhesive layer 6.

The adhesive layer 6 may be formed by any method, and examples thereof include a method of applying a liquid adhesive and a method of using a hot melt adhesive. Of these, the method of applying a liquid adhesive has a problem that air bubbles are easily entrained, but since the region to which the adhesive should be applied is appropriately divided by the portion 1044, the entrainment of air bubbles is suppressed. be able to. Further, even if air bubbles are involved, it is difficult to affect the core portion 14. As a result, it is possible to prevent the occurrence of defects due to the entrainment of bubbles.

Examples of the adhesive used for the adhesive layer 6 include an epoxy adhesive, an acrylic adhesive, a urethane adhesive, a silicone adhesive, an olefin adhesive, and various hot melt adhesives (polyester adhesive, modified olefin). System) and the like.

The elastic modulus of the adhesive layer 6 is not particularly limited, but is preferably about 100 to 20000 MPa, more preferably about 300 to 15000 MPa, further preferably about 500 to 12500 MPa, and particularly preferably about 1000 to 10000 MPa. It is said that. By setting the elastic modulus of the adhesive layer 6 within the above range, the adhesive layer 6 absorbs a load to some extent, alleviates the concentration of stress in the core portion 14, and provides sufficient adhesive force by the adhesive layer 6. Secure. As a result, a more reliable optical waveguide connection body 10 can be obtained.

The elastic modulus of the adhesive layer 6 is measured at a temperature of 25 ° C. according to the method specified in JIS K 7127.

Further, the retracted length L1 described above is also related to the length of the adhesive layer 6. When the receding length L1 is within the above range, the adhesive layer 6 can be provided in a sufficient area, so that the optical waveguide 1 and the optical interposer 2 can be bonded with sufficient strength. As a result, a more reliable optical waveguide connector 10 can be obtained.

Further, the core portion 14 and the side clad portion 15 may have different constituent materials from each other, but when both constituent materials are resin materials, it is preferable that the base polymer is the same as each other. As a result, the physical characteristics such as the thermal expansion coefficient and the elastic modulus are close to each other between the core portion 14 and the side clad portion 15. As a result, even when the environment in which the optical waveguide 1 is placed changes or the optical waveguide 1 is bent, the core portion 14 is deformed, the transmission efficiency in the core portion 14 is lowered, or the core portion 14 and light are used. It is possible to suppress a decrease in the optical coupling efficiency with the interposer 2. Further, there is an advantage that the core layer 13 can be easily manufactured and the dimensional accuracy of the core portion 14 can be easily improved.

The fact that the base polymers are the same as each other means that the structures of the main repeating units contained in the polymer having the highest compounding ratio in both constituent materials are the same as each other.

As a method of manufacturing the core layer 13 using a resin material, for example, the refractive index modulation ability (for example, photobleaching, monomer diffusion, photoisomerization, photodimerization, etc.) in which the refractive index changes by applying energy is used. A method of applying energy in a desired pattern to a film made of this composition by using a composition having an ability) can be mentioned. Note that photobleaching is a phenomenon in which the refractive index changes due to the breakage of bonds in the molecule with energy application, and monomer diffusion is a phenomenon in which polymers and monomers having different refractive indexes are used to apply energy. Along with this, it is a phenomenon in which the monomers dispersed in the polymer are unevenly distributed to form a refractive index distribution.

Therefore, by using the composition having the above-mentioned refractive index modulation ability, the core portion 14 and the side clad portion 15 can be easily and precisely formed in the film. That is, when energy is applied to the film made of the composition, a difference in refractive index can be generated between the region where energy is applied and the region where energy is not applied, so that the core portion 14 and the side clad portion 15 can be separated from each other. Can be formed. At this time, by clearly separating the region where energy is applied and the region where energy is not applied, a large difference in the refractive index is generated between the two regions. This makes it possible to form a refractive index distribution in a film made of the same base polymer.

Examples of the method of applying energy include a method of irradiating energy rays such as visible light, ultraviolet rays, lasers, and electron beams.

In addition, as a device used for irradiating energy rays, in addition to a device that selectively irradiates a specific area with an energy ray using a mask, a device that selectively irradiates an energy ray to a specific area without using a mask. (Maskless irradiation device) can be used. Since the maskless irradiation device can efficiently irradiate energy rays with high spatial resolution without using a mask, it is possible to reduce the processing cost and flexibly respond to different irradiation patterns. Therefore, it is possible to produce a wide variety of products in small quantities.

As the maskless irradiation device, various spatial light modulation elements such as a reflection type spatial light modulation element such as a digital micromirror device (DMD) and a transmission type spatial light modulation element such as a liquid crystal display element (LCD) are used. The one using is mentioned.

Examples of the composition having a refractive index modulation ability by photobleaching include the core film material described in JP-A-2009-145867.

Further, examples of the composition having a refractive index modulation ability by monomer diffusion include the photosensitive resin composition described in JP-A-2010-090328.

Examples of the composition having a refractive index modulation ability by photoisomerization include norbornene-based resins described in JP-A-2005-164650.

Further, examples of the composition having a refractive index modulation ability by photodimerization include the photosensitive resin composition described in JP-A-2011-105791.

(Optical connector)
As shown in FIG. 3, the optical connector 5 includes a connector main body 51 and a through hole 50 formed in the connector main body 51.

The optical waveguide 1 is adhered to the inner wall surface of the through hole 50 via an adhesive or the like. As a result, the optical connector 5 is fixed to the end of the optical waveguide 1. The optical connector 5 is configured to engage, for example, the optical connector 91 as shown in FIG. As a result, the optical waveguide 1 to which the optical connector 5 is mounted and the optical fiber 9 to which the optical connector 91 is mounted can be optically connected.

The outer shape of the connector main body 51 is not particularly limited, and may be a shape conforming to a rectangular parallelepiped as shown in FIGS. 1 and 3 or a shape other than that. Further, the connector main body 51 may include a portion conforming to various connector standards. Examples of such a connector standard include a small (Mini) MT connector, an MT connector specified in JIS C 5981, a 16 MT connector, a two-dimensional array type MT connector, an MPO connector, an MPX connector and the like.

Further, the optical connector 5 may be provided with an engaging means or the like for engaging with the optical connector 91. Examples of such engaging means include a means consisting of a guide pin and a guide hole, a means using locking by a claw, a clip, an adhesive and the like.

Examples of the constituent material of the connector main body 51 include various resin materials such as phenol-based resin, epoxy-based resin, olefin-based resin, urea-based resin, melamine-based resin, unsaturated polyester-based resin, polyphenylene sulfide-based resin, and stainless steel. , Various metal materials such as aluminum alloys and the like.

The optical connector 5 may be provided as needed or may be omitted. In that case, it may be connected to the optical fiber 9 without going through the optical connector 5, or may be connected to a light receiving / receiving element or an optical interposer (not shown).

(Mounting board)
The mounting board 3 is a board for mounting the optical waveguide 1, the optical connector 5, and the optical interposer 2. By using such a mounting substrate 3, the optical waveguide 1 and the optical interposer 2 can be stably held. At the same time, the mounting board 3 includes active components such as LSI (Large-Scale Integration), IC (Integrated Circuit), CPU (Central Processing Unit), RAM (Random Access Memory), capacitors, coils, resistors, diodes and the like. Electronic components such as passive components, light emitting diodes, laser diodes, and optical components such as light receiving sensors can be mixedly mounted. This makes it possible to construct a more sophisticated optical waveguide connection body 10.

The mounting substrate 3 includes an insulating substrate 31 and a conductive layer 32 (electrical wiring).
Of these, as the insulating substrate 31, any substrate having insulation and rigidity suitable for handling can be used. Specific examples thereof include various resin materials such as polyimide resins, polyamide resins, epoxy resins, various vinyl resins, and polyester resins such as polyethylene terephthalate resins. In addition, paper, glass cloth, resin film, etc. are used as the base material, and the base material is impregnated with resin materials such as phenol-based resin, polyester-based resin, epoxy-based resin, cyanate-based resin, polyimide-based resin, and fluorine-based resin. In addition to insulating substrates used for composite copper-clad laminates such as glass cloth / epoxy copper-clad laminates and glass non-woven fabrics / epoxy copper-clad laminates, polyetherimide resin substrates and poly Examples thereof include heat-resistant and thermoplastic organic rigid substrates such as ether ketone resin substrates and polysulfone resin substrates, and ceramics-based rigid substrates such as alumina substrates, aluminum nitride substrates, and silicon carbide substrates.

Further, the conductive layer 32 is provided inside or on the surface of the insulating substrate 31. Examples of the constituent material of the conductive layer 32 include simple metals such as copper, aluminum, nickel, chromium, zinc, tin, gold, and silver, or alloys containing these metal elements.

The mounting substrate 3 may be provided as needed, and may be omitted if, for example, only the connection between the optical waveguide 1 and the optical interposer 2 has sufficient rigidity.

(Optical interposer)
The optical interposer 2 includes an interposer substrate 21, a light guide unit 22, a conductive unit 23, a bump 24, a semiconductor element 25, and a light emitting / receiving element 26.

The interposer substrate 21 may be any substrate as long as the light guide portion 22 and the conductive portion 23 can be mixedly mounted.
The light guide unit 22 optically connects the light receiving / receiving element 26 and the optical waveguide 1. That is, the light guide portion 22 is provided so as to extend from the vicinity of the light receiving / receiving element 26 to the region in contact with the optical waveguide 1.

Further, as shown in FIGS. 6 and 7, the light guide portion 22 is arranged so that the center of the width of the core layer 13 coincides with the center of the width of the core portion 14 when the core layer 13 is viewed in a plan view. preferable. By arranging in this way, it becomes easy to secure the maximum area where both sides overlap in a plan view. Thereby, the optical coupling efficiency between the optical waveguide 1 and the optical interposer 2 can be further improved.

The fact that the center of the width of the light guide portion 22 and the center of the width of the core portion 14 coincide with each other means that the misalignment is 20% or less of the width of the core portion 14.

Further, it is preferable that the optical axis of the light guide portion 22 and the optical axis of the core portion 14 are parallel to each other. By arranging in this way, it becomes easy to secure the maximum area where both sides overlap in a plan view. Thereby, the optical coupling efficiency between the optical waveguide 1 and the optical interposer 2 can be further improved.

The fact that the optical axis of the light guide unit 22 and the optical axis of the core unit 14 are parallel to each other means a state in which the angle deviation is 1 ° or less.

The conductive portion 23 electrically connects the semiconductor element 25 or the light receiving / receiving element 26 to the bump 24. That is, the conductive portion 23 is provided so as to extend from the vicinity of the semiconductor element 25 and the light receiving / receiving element 26 to the bump 24.

Further, the semiconductor element 25 and the light emitting / receiving element 26 do not have to be individual elements, and may be a composite element in which both are combined.

The optical waveguide connector 10 provided with the optical interposer 2 as described above is controlled by a control element such as an LSI mounted on the mounting board 3, and functions as an optical transceiver that transmits or receives an optical signal. That is, it is inserted between the control element and the optical fiber 9 and is responsible for electrical / optical conversion, thereby contributing to the construction of optical communication between chips, boards, and servers, for example.

<Modification example of optical waveguide connector>
Next, a modification of the optical waveguide connector according to the present embodiment will be described.

FIG. 8 is a vertical sectional view showing a modified example of the optical waveguide connector shown in FIG. 7. In the following description, for convenience of explanation, the upper part of FIG. 8 is referred to as “upper” and the lower part is referred to as “lower”.

Hereinafter, the optical waveguide connection body according to the modified example will be described, but in the following description, the differences from the optical waveguide connection body shown in FIG. 7 will be mainly described, and the description thereof will be omitted for the same matters.

The optical waveguide connection 10 shown in FIG. 8 is the same as the optical waveguide connection 10 shown in FIG. 7, except that the light guide portion 22 included in the optical interposer 2 is provided so as to project from the lower surface of the interposer substrate 21. The same is true.

The light guide portion 22 projecting in this way is arranged so that the lower surface thereof and the upper surface of the core portion 14 of the optical waveguide 1 are in contact with each other. In other words, the light guide portion 22 penetrates the adhesive layer 6 interposed between the core layer 13 of the optical waveguide 1 and the optical interposer 2.

Even with the optical waveguide connecting body 10 as described above, the same effect as that of the optical waveguide connecting body 10 shown in FIG. 7 can be obtained.

The protruding light guide portion 22 does not have to protrude in its entire thickness, and only a part of its thickness may protrude.

Further, the light guide portion 22 and the core portion 14 do not necessarily have to be in contact with each other, and for example, a thin adhesive layer 6 or other elements may be interposed between them.

The protrusion length L2 (see FIG. 6) of the portion 1045 corresponding to the side clad portion 15 is not particularly limited, but is preferably about 50 to 150% of the protrusion length of the light guide portion 22, and is preferably 80 to 80. It is more preferably about 120%. By setting the relationship between the protrusion length L2 of the portion 1045 and the protrusion length of the light guide portion 22 within the above range, it is possible to suppress the concentration of large stress in the core portion 14 and to suppress the concentration of large stresses in the core portion 14 and the light guide portion 22 and the core portion. 14 can be held closer to each other. Therefore, the optical coupling efficiency between the optical waveguide 1 and the optical interposer 2 can be further improved.

<Electronic equipment>
As described above, the optical waveguide 10 as described above is highly reliable because the optical waveguide 1 and the optical interposer 2 are connected with good optical coupling efficiency. Therefore, by providing the optical waveguide connecting body 10, a highly reliable electronic device (embodiment of the electronic device of the present invention) capable of performing high-quality optical communication can be obtained.

Examples of such electronic devices include electronic devices such as smartphones, tablet terminals, mobile phones, game machines, router devices, WDM (Wavelength Division Multiplex) devices, personal computers, televisions, and home servers. In any of these electronic devices, it is necessary to transmit a large amount of data at high speed between an arithmetic unit such as an LSI and a storage device such as a RAM. Therefore, when such an electronic device is provided with the optical waveguide connector 10, problems such as noise and signal deterioration peculiar to electric wiring are eliminated, and a dramatic improvement in its performance can be expected.

Further, in the optical waveguide portion, the amount of heat generated is significantly reduced as compared with the electric wiring. Therefore, the power required for cooling can be reduced, and the power consumption of the entire electronic device can be reduced.

The optical waveguide, the optical waveguide connector, and the electronic device have been described above based on the illustrated embodiments, but the present invention is not limited thereto.

For example, any element may be added to the embodiment, or the element included in the embodiment may be replaced with an element having the same function.

1 Optical Waveguide 2 Optical Interposer 3 Mounting Board 5 Optical Connector 6 Adhesive Layer 9 Optical Fiber 10 Optical Waveguide Connection 11 First Clad Layer 12 Second Clad Layer 13 Core Layer 14 Core 15 Side Clad 16 Support Layer 17 Cover Layer 21 Interposer board 22 Light guide part 23 Conductive part 24 Bump 25 Semiconductor element 26 Light receiving element 31 Insulation board 32 Conductive layer 50 Through hole 51 Connector body 91 Optical connector 101 Left end surface 102 Right end surface 103 Bottom surface 104 Top surface 105 Left top surface 121 Left end Surface 1044 Part 1045 Part L1 Retreat length L2 Overhang length t Thickness

Claims (10)

A core layer including a core portion and a side surface clad portion adjacent to the side surface of the core portion, and having a first main surface and a second main surface which are in a front-to-back relationship with each other.
The first clad layer laminated on the first main surface and
Have,
The core layer is made of a resin material and is made of a resin material.
The base polymer of the core portion and the base polymer of the side clad portion are the same.
The second main surface is an optical coupling surface that includes a clad-corresponding portion corresponding to the side surface clad portion and a core-corresponding portion corresponding to the core portion, and the core-corresponding portion is coupled to another optical component. ,
The clad-corresponding portion protrudes from the core-corresponding portion in the thickness direction of the core layer.
An optical waveguide characterized in that L2 / t is 0.01 to 20% when the protruding length of the clad-corresponding portion is L2 and the thickness of the core portion is t. The optical waveguide according to claim 1, wherein the coupling between the other optical component and the optical coupling surface is an adibatic coupling. Further, it has a second clad layer laminated on the second main surface.
The optical waveguide according to claim 1 or 2 , wherein the end face of the second clad layer is recessed from the end face of the core portion . The optical waveguide according to claim 3, wherein the receding length L1 of the end face of the second clad layer is 10 to 10000 when the average width of the core portion is 1. The optical waveguide according to claim 4, wherein a portion of the second main surface on which the second clad layer is not laminated is exposed. The optical waveguide according to any one of claims 1 to 5, wherein the refractive index distribution of the core layer is a distribution in which the refractive index continuously changes in the width direction of the core portion. The optical waveguide according to any one of claims 1 to 6, further comprising a support layer laminated on the side opposite to the core layer of the first clad layer. The optical waveguide according to any one of claims 1 to 7, wherein the waveguide mode of the core portion is a single mode. The optical waveguide according to any one of claims 1 to 8.
Optical components optically connected to the optical waveguide,
An optical waveguide connector characterized by having. An electronic device comprising the optical waveguide connector according to claim 9.

Images