JP2015094846A - Optical waveguide, optoelectronic hybrid substrate and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical waveguide, optoelectronic hybrid substrate and electronic apparatus which can suppresses the occurrence of an opening.SOLUTION: An optical waveguide 1 has a laminate 10 in which a cladding layer 11, a core layer 13 with a core part 14 formed and a cladding layer 12 are laminated, and a notch 170 formed from the cladding layer 12 side to the core part 14 and having a mirror face 171 inclined relative to the axis of the core part 14. A contour line 179 of the inclined face 171 on the cladding layer 11 side has both ends 179a, 179b closer to the cladding layer 11 side than a central part 179c.

Description

  The present invention relates to an optical waveguide, an opto-electric hybrid board, and an electronic device.

  Conventionally, as a method of manufacturing an optical waveguide having an inclined surface (mirror surface), a second cladding is applied to a laminate in which a first cladding layer, a core layer on which a core portion is formed, and a second cladding layer are stacked. A method of forming an inclined surface by cutting an optical waveguide from a layer side with a tapered blade to form a notch is known (for example, see Patent Documents 1 and 2). However, in the optical waveguides of Patent Documents 1 and 2, the blade tip is a straight line (or a surface having a fine width) parallel to the surface direction of the laminate (see FIG. 6). As a result, the following problems occur.

  The notch formed by the blade is preferably not penetrated through the surface of the laminate on the first cladding layer side. This is because, if the notch penetrates the surface on the first cladding layer side, dust, dust, moisture, etc. intrude into the notch from the opening, and these contaminate the reflective surface, This is because the light reflection efficiency may decrease. In order to prevent the notch from penetrating to the surface on the first cladding layer side, high-precision control of the blade is necessary. However, since the thickness of the laminated body is thin, high-precision control of the blade is extremely difficult. When a notch is formed using a blade as in Patent Document 1, there is no problem if the cutting depth of the blade (depth of penetration into the laminate) is a desired depth. For example, the cutting depth of the blade When the depth becomes deeper than the desired depth, the entire tip of the blade simultaneously penetrates the laminate, and the opening formed in the surface on the first cladding layer side becomes large, and the above problem occurs more remarkably. (See FIG. 6).

JP 2008-304870 A Japanese Patent Application Laid-Open No. 11-258953

  An object of the present invention is to provide an optical waveguide, an opto-electric hybrid board, and an electronic device that can suppress the generation of openings.

Such an object is achieved by the present inventions (1) to (9) below.
(1) a laminated body in which a first cladding layer, a core layer in which a core portion is formed, and a second cladding layer are laminated;
A notch provided with an inclined surface that is formed from the second cladding layer side toward the core portion and is inclined with respect to the axis of the core portion;
The optical waveguide according to claim 1, wherein a contour line on the first clad layer side of the inclined surface is positioned on the first clad layer side with respect to both ends thereof.

(2) The optical waveguide according to (1), wherein the outline is curved in a concave shape.
(3) The optical waveguide according to (1) or (2), wherein both ends of the contour line are located in the first cladding layer.

  (4) The optical waveguide according to (1) or (2), wherein both ends of the contour line are located in the core layer.

  (5) The optical waveguide according to any one of (1) to (3), wherein a center portion and an end portion of the contour line are located in different layers of the stacked body.

  (6) The optical waveguide according to any one of (1) to (5), wherein the inclined surface is a curved convex surface.

  (7) The optical waveguide according to any one of (1) to (5), wherein the inclined surface is a flat surface.

(8) The optical waveguide according to any one of (1) to (7),
An opto-electric hybrid board, comprising: an electric wiring board laminated on the optical waveguide and provided with electric wiring on a surface thereof.
(9) An electronic apparatus comprising the opto-electric hybrid board according to (8).

According to the present invention, an optical waveguide capable of suppressing the generation of openings can be obtained.
In addition, according to the present invention, a highly reliable opto-electric hybrid board and electronic apparatus having such an optical waveguide can be obtained.

It is a perspective view which permeate | transmits and shows 1st Embodiment of the optical waveguide of this invention. It is a longitudinal cross-sectional view of the optical waveguide shown in FIG. It is sectional drawing which looked at the notch which the optical waveguide shown in FIG. 1 has seen from the arrow B direction in FIG. It is a top view of the notch which the optical waveguide shown in FIG. 1 has. It is a perspective view which shows the notch which the optical waveguide shown in FIG. 1 has. It is a figure which compares this invention and a prior art example. It is a longitudinal cross-sectional view which shows the other structural example of the mirror which concerns on 1st Embodiment. It is sectional drawing which shows the notch of 2nd Embodiment of the optical waveguide of this invention. It is sectional drawing which shows the notch of 3rd Embodiment of the optical waveguide of this invention. It is a longitudinal cross-sectional view which shows the notch of 4th Embodiment of the optical waveguide of this invention. It is a top view of the notch shown in FIG. It is a longitudinal cross-sectional view of 5th Embodiment of the optical waveguide of this invention. It is a longitudinal cross-sectional view of 6th Embodiment of the optical waveguide of this invention. It is sectional drawing which shows the notch of 7th Embodiment of the optical waveguide of this invention. It is a longitudinal cross-sectional view which shows embodiment of the opto-electric hybrid board | substrate of this invention.

  Hereinafter, the optical waveguide, the opto-electric hybrid board and the electronic apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<Optical waveguide>
<< First Embodiment >>
First, a first embodiment of the optical waveguide of the present invention will be described.

  FIG. 1 is a partially transparent perspective view showing a first embodiment of an optical waveguide of the present invention, FIG. 2 is a longitudinal sectional view of the optical waveguide shown in FIG. 1, and FIG. 3 is an optical waveguide shown in FIG. 2 is a cross-sectional view of the notch that is seen from the direction of arrow B in FIG. 2, FIG. 4 is a top view of the notch that the optical waveguide shown in FIG. 1 has, and FIG. 5 is the notch that the optical waveguide shown in FIG. FIG. 6 is a perspective view showing a comparison between the present invention and a conventional example, and FIG. 7 is a longitudinal sectional view showing another configuration example of the mirror according to the first embodiment.

  An optical waveguide 1 shown in FIG. 1 has a band shape, and transmits an optical signal between a light incident portion and a light emitting portion to perform optical communication.

  An optical waveguide 1 shown in FIG. 1 includes a laminate 10 in which a clad layer (first clad layer) 11, a core layer 13, and a clad layer (second clad layer) 12 are laminated from below. In the core layer 13, a long core portion 14 and a side clad portion 15 provided adjacent to the side surface are formed. As a result, the core part 14 is surrounded by the clad part (the side clad part 15 and the clad layers 11 and 12), and light can be confined and propagated in the core part 14. The optical waveguide 1 is provided with a notch 170 formed in the laminate 10. In the following, the surface on the cladding layer 11 side of the laminate 10 is referred to as a surface 10a, and the surface on the cladding layer 12 side is referred to as a surface 10b.

  Although the refractive index of the core part 14 should just be larger than the refractive index of a clad part, it is preferable that the difference is 0.3% or more, and it is more preferable that it is 0.5% or more. On the other hand, the upper limit value is not particularly set, but is preferably about 5.5%. If the difference in refractive index is less than the lower limit value, the effect of propagating light may be reduced. On the other hand, if the difference in refractive index exceeds the upper limit value, further improvement in light transmission efficiency cannot be expected.

  The refractive index difference is expressed by the following equation when the maximum refractive index of the core portion 14 is n4 and the minimum refractive indexes of the side cladding portion 15, the cladding layer 11, and the cladding layer 12 are n5, n1, and n2. Is done.

Refractive index difference (%) = | n4 / n5-1 | × 100
Refractive index difference (%) = | n4 / n1-1 | × 100
Refractive index difference (%) = | n4 / n2-1 | × 100

  Further, the refractive index distribution in the width direction of the core layer 13 (the thickness direction in FIG. 2) may be any shape distribution. That is, the refractive index distribution may be a so-called step index (SI) type distribution in which the refractive index changes discontinuously, or a so-called graded index (GI) type distribution in which the refractive index changes continuously. It may be. If the SI type distribution is used, it is easy to form a refractive index distribution. If the GI type distribution is used, the probability that the signal light is collected in a region having a high refractive index is increased, so that the transmission efficiency is improved.

  On the other hand, the refractive index distribution in the thickness direction of the optical waveguide 1 (vertical direction in FIG. 2) may be the above-described step index distribution or the above-described graded index distribution.

  Further, the core portion 14 may be linear or curved in plan view. Furthermore, the core part 14 may branch or cross | intersect on the way.

  The cross-sectional shape of the core portion 14 is not particularly limited, and may be 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. By being (rectangular), there is an advantage that the core portion 14 can be easily formed.

  The width and height (the thickness of the core layer 13) of the core part 14 are not particularly limited, but are preferably about 1 to 200 μm, more preferably about 5 to 100 μm. Thereby, it is possible to increase the density of the core part 14 while increasing the transmission efficiency of the core part 14. That is, since the number of core portions 14 that can be laid per unit area can be increased, large-capacity optical communication can be performed even in a small area.

  In addition, the number of the core parts 14 formed in the core layer 13 is not particularly limited, but is 1 to 100, for example.

  The constituent materials (main materials) of the core layer 13 and the cladding layers 11 and 12 as described above are, for example, acrylic ether, methacrylic resin, polycarbonate, polystyrene, cyclic ether resin such as epoxy resin and oxetane resin. , Polyamide, polyimide, polybenzoxazole, polysilane, polysilazane, silicone resin, fluorine resin, polyurethane, polyolefin resin, polybutadiene, polyisoprene, polychloroprene, polyester such as PET and PBT, polyethylene succinate, polysulfone, poly Various resin materials such as ethers and cyclic olefin resins such as benzocyclobutene resins and norbornene resins can be used. Note that the resin material may be a composite material in which materials having different compositions are combined. Since these are relatively easy to process, they are suitable as constituent materials for the core layer 13 and the cladding layers 11 and 12 in which the notches 170 are formed.

  The optical waveguide 1 is provided with a notch 170 in which a part of the laminated body 10 is removed from the surface 10b side. That is, the optical waveguide 1 includes the laminated body 10 and a notch 170 formed thereon. The notch 170 shown in FIG. 1 is located in the middle of the core part 14 in the longitudinal direction. The method for forming the notch 170 is not particularly limited, and can be formed by, for example, a patterning method using a photolithography technique and an etching technique, a laser processing method using a mask, or the shape of the notch 170. It can also be formed by an imprint method in which a mold (blade) corresponding to the above is pressed.

  As shown in FIG. 2, a part of the inner surface of the notch 170 is inclined surfaces (transverse sections) 171 and 172 that are inclined with respect to the axis A of the core portion 14. The inclined surface 171 functions as a mirror surface (optical path conversion unit) that converts the optical path of the core unit 14. The inclined surface 171 changes the propagation direction by reflecting light propagating from the right side to the left side in FIG. Note that the inclined surface 172 may be used as a mirror surface in the same manner as the inclined surface 171.

  Each of the inclined surfaces 171 and 172 is a flat surface. Thereby, the diffusion of the light reflected by the inclined surface 171 can be reduced, and the light reflection characteristics on the inclined surface 171 can be enhanced.

  Further, as shown in FIG. 3, the contour line 179 on the surface 10a side of the inclined surface 171 is curved in a concave shape, and both end portions 179a and 179b are located on the surface 10a side with respect to the central portion 179c.

  The entire area of the contour line 179 is located in the cladding layer 11 (in the middle of the thickness direction of the cladding layer 11). Thereby, a large area of the inclined surface 171 can be ensured, and the light reflection characteristics on the inclined surface 171 can be enhanced.

As described above, since the inclined surfaces 171 and 172 are both flat surfaces and the contour line 179 is curved in a concave shape, the notch 170 has a shape as shown in FIGS. As illustrated, the notch 170 has a bottom surface 178 which is curved corresponding to the contour line 179, the width W ₁ of the bottom surface 178 is gradually increased from the both ends toward the central portion. That is, located closest to the surface 10a side width W ₁ is the both end portions of the minimum width W ₁ is located far from the maximum of the center portion is most surface 10a. The width _{W 1} of the end portions is substantially 0, the inclined surfaces 171 and 172 are in contact (connected) at the portion. Therefore, the cross-sectional shape of the notch 170 has a substantially trapezoidal shape in the cross-section taken along the line CC in FIG. 4, and the cross-sectional shape of the notch 170 has a substantially cross-sectional shape in the cross-section taken along the line DD and EE in FIG. It is a triangle. However, the width W _{1 at} both ends may not be 0, and the cross-sectional shape of the notch 170 is substantially trapezoidal in each of the cross section taken along the line CC, the line DD, and the line EE in FIG. You may have done.

  By forming the notch 170 (contour line 179) in such a shape, the following effects can be exhibited as compared with the conventional case where the contour line 179 is a straight line parallel to the surface 10a. it can. Even if the notch 170 is formed deeper than the set value in the manufacturing process of the optical waveguide 1 and the notch 170 penetrates to the surface 10a as shown in FIG. 6, the surface 10a formed by the penetration is provided. The opening 9 can be made smaller than before. Therefore, intrusion of dust, dirt, moisture and the like from the opening 9 formed on the surface 10a is suppressed, and contamination of the inclined surfaces 171 and 172 is suppressed.

  Here, the minimum value of the gap G between the both end portions 179a, 179b and the central portion 179c of the contour line 179 is not particularly limited, and varies depending on the formation accuracy of the notch 170 and the width of the notch 170. It is preferably about 5 to 300 μm, and more preferably about 2 to 200 μm. Thereby, the opening 9 formed in the surface 10a due to a manufacturing error can be further reduced.

  The curvature radius (average curvature radius) of the contour line 179 is not particularly limited, and varies depending on the formation accuracy of the notch 170, but is preferably about 2000 μm or less, more preferably about 1000 μm or less. preferable. Thereby, the opening 9 formed in the surface 10a due to a manufacturing error can be further reduced. In addition, the curvature radius of the outline 179 may be constant over the whole area, and may differ in each part. For example, the curvature radii of both end portions 179a and 179b may be larger than the curvature radius of the central portion 179c, and conversely, the curvature radii of both end portions 179a and 179b may be smaller than the curvature radius of the central portion 179c.

  The notch 170 has been described above. The maximum depth D of the notch 170 is appropriately set based on the thickness of the laminated body 10 and is not particularly limited. However, from the viewpoint of the mechanical strength and flexibility of the optical waveguide 1, it is about 1 to 500 μm. It is preferable to set it to about 5 to 400 μm.

  Further, the maximum length L of the notch 170 is not particularly limited, but is about 2 to 1200 μm from the relationship between the thickness of the cladding layers 11 and 12 and the core layer 13 and the inclination angle of the inclined surfaces 171 and 172. It is preferable to set it to about 10 to 1000 μm.

  Furthermore, the maximum width W of the notch 170 is not particularly limited, and is appropriately set according to the width of the core portion 14, the pitch of the core portion 14, the number of lines of the core portion 14, and the like, but about 1 to 10000 μm. Is preferable, and it is more preferable to set it as about 5-6000 micrometers.

  Note that one notch 170 may be provided for one core part 14, but one notch 170 may be provided so as to straddle the plurality of core parts 14.

  FIG. 7 is a longitudinal sectional view showing another configuration example of the mirror according to the first embodiment. In FIG. 1, the inclined surface 171 forms a mirror, whereas in FIG. 7, the inclined surface 171 and the reflective film 176 formed thereon form a mirror. . Otherwise, the optical waveguide 1 shown in FIG. 4 is the same as the optical waveguide 1 shown in FIG.

  By providing such a reflective film 176, the light reflection characteristics of the mirror can be particularly improved. Examples of the reflective film 176 include a metal film, a carbon film, a resin film, a ceramic film, and a silicon film. Among these, a metal film is preferably used. According to the metal film, the reflection film 176 having a high reflectance due to the gloss peculiar to the metal can be obtained. Examples of the constituent material of the metal film include aluminum, iron, chromium, nickel, copper, zinc, silver, platinum, gold, lead and the like.

  The average thickness of the reflective film 176 is not particularly limited, but is preferably about 0.1 to 500 μm, and more preferably about 0.5 to 300 μm. As a result, a reflective film that has sufficient reflectivity and is difficult to peel off can be obtained.

  Examples of the method for forming the reflective film 176 include a vacuum deposition method, a physical vapor deposition method such as a sputtering method, a chemical vapor deposition method such as a CVD method, a plating method, a thermal transfer method, a metal foil transfer method, a printing method, and a coating method. Etc.

<< Second Embodiment >>
Next, a second embodiment of the optical waveguide of the present invention will be described.

  FIG. 8 is a cross-sectional view showing a cutout in the second embodiment of the optical waveguide of the present invention. FIG. 8 corresponds to FIG. 3 described above.

  Hereinafter, although 2nd Embodiment is described, in the following description, difference with 1st Embodiment is demonstrated and the description is abbreviate | omitted about the same matter.

  The optical waveguide 1 according to the second embodiment shown in FIG. 8 is the same as the optical waveguide 1 according to the first embodiment except that the configuration of the notch 170 is different.

In the optical waveguide 1 according to the first embodiment described above, the entire area of the contour line 179 of the inclined surface 171 is located in the cladding layer 11, whereas in the optical waveguide 1 according to the present embodiment, FIG. As shown, the entire area of the contour line 179 of the inclined surface 171 is located in the core layer 13. That is, the notch 170 does not reach the cladding layer 11. Thereby, since the boundary between the core layer 13 and the clad layer 11 is not exposed in the notch 170, it is possible to effectively prevent the occurrence of peeling or the like starting from the boundary. Therefore, for example, the optical waveguide 1 is excellent in mechanical strength as compared with the first embodiment described above.
In such a second embodiment, the same operations and effects as in the first embodiment can be obtained.

«Third embodiment»
Next, a third embodiment of the optical waveguide of the present invention will be described.

  FIG. 9 is a cross-sectional view showing a cutout in the third embodiment of the optical waveguide of the present invention. FIG. 9 is a diagram corresponding to FIG. 3 described above.

  Hereinafter, the third embodiment will be described. In the following description, differences from the first embodiment will be described, and description of similar matters will be omitted.

In the optical waveguide 1 according to the first embodiment described above, the entire area of the contour line 179 of the inclined surface 171 is located in the clad layer 11, whereas in the optical waveguide 1 according to the present embodiment, FIG. As shown, both end portions 179 a and 179 b of the contour line 179 of the inclined surface 171 are located in the clad layer 11 and located in the central portion 179 c core layer 13. That is, both end portions 179 a and 179 b and the central portion 179 c are located in different layers of the stacked body 10. As a result, the entire length of the boundary between the core layer 13 and the cladding layer 11 exposed at the notch 170 can be shortened compared to the optical waveguide 1 of the first embodiment described above, and the occurrence of peeling starting from the boundary is generated. Etc. can be effectively suppressed. Further, since the area of the region crossing the core portion 14 is larger than that in the second embodiment described above, the light reflection characteristics on the inclined surface 171 are improved. That is, according to the optical waveguide 1 of the present embodiment, the effects of the first embodiment and the effects of the second embodiment can be compromised.
In such a third embodiment, the same operation and effect as in the first embodiment can be obtained.

<< Fourth Embodiment >>
Next, a fourth embodiment of the optical waveguide of the present invention will be described.

  FIG. 10 is a longitudinal sectional view showing a cutout of the fourth embodiment of the optical waveguide of the present invention, and FIG. 11 is a top view of the cutout shown in FIG. 9 is a diagram corresponding to FIG. 3 described above, and FIG. 11 is a diagram corresponding to FIG. 4 described above.

  Hereinafter, although 4th Embodiment is described, in the following description, a difference with 1st Embodiment is demonstrated and the description is abbreviate | omitted about the same matter.

In the optical waveguide 1 according to the first embodiment described above, the inclined surfaces 171 and 172 are formed as flat surfaces, whereas in the optical waveguide 1 according to the present embodiment, as shown in FIG. Reference numerals 171 and 172 are both curved convex surfaces (curved surfaces convex toward the inside of the notch 170). Thus, since the inclined surface is configured by a curved convex surface, the notch 170 of the present embodiment does not have the bottom surface 178, and the inclined surface is formed throughout the contour line 179, that is, without passing through another surface. 171 and 172 are connected. Thus, according to the present embodiment, since the bottom surface is not formed in the notch 170, the area of the opening 9 that is formed due to a manufacturing error can be reduced as compared with the first embodiment. Furthermore, since the inclined surface 171 is a curved convex surface as described above, the reflected light can be collected and more efficient light propagation can be performed.
In such a fourth embodiment, the same operations and effects as in the first embodiment can be obtained.

«Fifth embodiment»
Next, a fifth embodiment of the optical waveguide of the present invention will be described.
FIG. 12 is a longitudinal sectional view showing a fifth embodiment of the optical waveguide of the present invention.

  Hereinafter, the fifth embodiment will be described. In the following description, differences from the first embodiment will be described, and description of similar matters will be omitted.

In the optical waveguide 1 according to the first embodiment described above, the inclined surface 172 is an inclined surface similar to the inclined surface 171, whereas in the optical waveguide 1 according to the present embodiment, the inclined surface 172 has an axis line. It is a flat upright surface 172 ′ that is substantially orthogonal to A.
Also in the fifth embodiment, the same operation and effect as in the first embodiment can be obtained.

<< Sixth Embodiment >>
Next, a sixth embodiment of the optical waveguide of the present invention will be described.
FIG. 13 is a longitudinal sectional view of a sixth embodiment of the optical waveguide of the present invention.

  Hereinafter, the sixth embodiment will be described. In the following description, differences from the first embodiment will be described, and description of similar matters will be omitted.

  The optical waveguide 1 according to the seventh embodiment shown in FIG. 13 further includes a support film 2 laminated on the lower surface (surface 10a) of the cladding layer 11, and a cover film laminated on the upper surface (surface 10b) of the cladding layer 12. 3 is provided.

Further, the notch 170 is configured to penetrate the cover film 3. Therefore, the inclined surface 171 is a surface formed continuously from the cover film 3 through the cladding layer 12 and the core layer 13 to the middle of the cladding layer 11.
In such a sixth embodiment, the same operation and effect as in the first embodiment can be obtained.

  Moreover, by using the support film 2 and the cover film 3, the laminated body 10 can be protected from external force, foreign matter adhesion, contamination, and the like.

  Moreover, since the inclined surface 171 includes the cross section of the cover film 3, it has a wider area. For this reason, it becomes easy to form the inclined surface 171 with higher accuracy. That is, as the surface to be processed is wider, the processing accuracy of the cross section of the core portion 14 can be easily increased. Therefore, according to the sixth embodiment, a mirror with particularly high reflection efficiency can be formed.

<< Seventh Embodiment >>
Next, a seventh embodiment of the optical waveguide of the present invention will be described.

  FIG. 14 is a cross-sectional view showing a cutout in the seventh embodiment of the optical waveguide of the present invention. FIG. 14 corresponds to FIG. 3 described above.

  Hereinafter, the eighth embodiment will be described, but in the following description, differences from the above-described embodiment will be described, and description of similar matters will be omitted.

  The optical waveguide 1 according to the seventh embodiment shown in FIG. 14 is the same as the optical waveguide 1 according to the sixth embodiment except that the configuration of the notch 170 is different.

  In the optical waveguide 1 according to the sixth embodiment described above, the notch 170 reaches the cladding layer 11, whereas in the optical waveguide 1 according to the present embodiment, the notch 170 reaches the support film 2. ing.

At this time, as shown in FIG. 14 (a), the entire region of the contour line 179 may be located in the support film 2, or as shown in FIG. 14 (b), both end portions 179a of the contour line 179, 179b may be located in the support film 2, and the center part 179c may be located in the clad layer 11, and both ends 179a and 179b of the contour line 179 are the support film 2 as shown in FIG. The central portion 179 c may be located in the core layer 13. In particular, according to the configuration of FIGS. 14B and 14C, compared with the configuration of FIG. 14A, the boundary between the core layer 13 and the cladding layer 11 exposed in the notch 170, the cladding layer 11 And the support film 2 can be shortened, and the occurrence of peeling and the like starting from the boundary can be effectively suppressed.
In the seventh embodiment, the same operation and effect as in the first embodiment can be obtained.

<Opto-electric hybrid board>
Next, an embodiment of the opto-electric hybrid board according to the present invention will be described.

FIG. 15 is a longitudinal sectional view showing an embodiment of the opto-electric hybrid board according to the present invention.
An opto-electric hybrid board 100 shown in FIG. 15 includes an optical waveguide 1 (the optical waveguide of the present invention), an electric wiring board 5 laminated on the upper surface thereof, and an adhesive sheet 90 that is interposed between them to bond them together. ,have.

  An electrical wiring board 5 shown in FIG. 15 has a multilayer board 50 having a core board 51 and build-up layers 52 laminated on both sides thereof, and bumps 53 provided on the lower surface of the multilayer board 50. ing.

  The core substrate 51 is a substrate that supports the electrical wiring substrate 5, and examples of the constituent material thereof include various resin materials. In addition, paper, glass cloth, resin film, etc. as a base material, and the base material impregnated with a resin material, specifically, glass cloth / epoxy copper clad laminate, glass nonwoven fabric / epoxy copper clad laminate In addition to insulating substrates used for composite copper-clad laminates such as heat-resistant and thermoplastic organic rigid substrates such as polyetherimide resin substrates, polyetherketone resin substrates, polysulfone resin substrates, alumina substrates, and nitriding It may be a ceramic rigid substrate such as an aluminum substrate or a silicon carbide substrate.

  Each of the conductor layer 522 and the through wiring is made of a conductive material such as a simple metal such as copper, aluminum, nickel, chromium, zinc, tin, gold, silver, or an alloy containing these metal elements. .

  The insulating layer 521 is made of a silicon compound such as silicon oxide or silicon nitride, a resin material such as a polyimide resin or an epoxy resin, or the like.

  In this way, an electrical circuit that extends not only in the plane direction but also in the thickness direction can be constructed in the buildup layer 52, and the density of the electrical circuit can be increased.

  In addition, although such a multilayer substrate 50 may be formed by what kind of construction method, it is formed by various buildup construction methods, such as an additive method, a semi-additive method, and a subtractive method, as an example.

  The electrical wiring board provided in the opto-electric hybrid board of the present invention is not limited to the one including the multilayer board such as the electrical wiring board 5 described above. For example, the multilayer board is a single-layer electrical wiring board (rigid board). It may be replaced, or may be replaced with various flexible substrates such as a polyimide substrate, a polyester substrate, and an aramid film substrate. The multilayer substrate 50 can be replaced with a coreless multilayer substrate that does not include the core substrate 51.

  Further, the electrical wiring substrate 5 shown in FIG. 15 has a solder resist layer 54 provided on the upper surface of the multilayer substrate 50. By providing the solder resist layer 54, the conductor layer 522 of the electrical wiring board 5 is protected from oxidation, corrosion, and the like.

  Note that an electrical element (not shown) may be mounted on the electrical wiring board 5. Examples of the electric element include IC, LSI, RAM, ROM, capacitor, coil, resistor, and diode.

  Further, the opto-electric hybrid board 100 shown in FIG. 15 has an optical element 6 mounted on the electric wiring board 5.

  The optical element 6 shown in FIG. 15 has an element body 60, a light emitting / receiving portion 61 and a terminal 62 provided on the lower surface of the element body 60, and a bump 63 provided so as to protrude downward from the terminal 62. ing. The light emitting / receiving unit refers to a light receiving unit, a light emitting unit, or a unit having both functions.

  The optical element 6 is arranged such that the optical axis of the light emitting / receiving unit 61 coincides with the axis of the core unit 14 via the inclined surface 171 (mirror) of the notch 170 of the optical waveguide 1. Thereby, the optical waveguide 1 and the optical element 6 are optically connected, and the optical signal propagating through the optical waveguide 1 is received by the optical element 6, or the optical signal emitted from the optical element 6 is incident on the optical waveguide 1. You can do it.

  Examples of the optical element 6 include a light emitting element such as a surface emitting laser (VCSEL), a light emitting diode (LED), and an organic EL element, and a light receiving element such as a photodiode (PD, APD).

<Electronic equipment>
The optical waveguide according to the present invention as described above has high transmission efficiency and excellent optical coupling efficiency with other optical components. For this reason, by providing the optical waveguide of the present invention, a highly reliable electronic device (electronic device of the present invention) capable of performing high-quality optical communication can be obtained.

  Examples of the electronic device including the optical waveguide of the present invention include electronic devices such as a mobile phone, a game machine, a router device, a WDM device, a personal computer, a television, and a home server. In any of these electronic devices, it is necessary to transmit a large amount of data at high speed between an arithmetic device such as an LSI and a storage device such as a RAM. Therefore, since such an electronic device includes the optical waveguide of the present invention, problems such as noise and signal degradation peculiar to electric wiring are eliminated, and a dramatic improvement in performance can be expected. This can contribute to cost reduction.

  In addition, the amount of heat generated in the optical waveguide portion is greatly reduced compared to electrical wiring. For this reason, the electric power required for cooling can be reduced and the power consumption of the whole electronic device can be reduced.

  The optical waveguide, the opto-electric hybrid board, and the electronic device of the present invention have been described above. However, the present invention is not limited to this, and for example, an arbitrary component may be added to the optical waveguide.

  In addition, when the inclined surface 171 is used as a light incident side mirror, the light emitting side may emit light from the end surface of the core portion 14 along the axis of the core portion 14. A connector may be attached. On the other hand, when the inclined surface is used as a light output side mirror, the light incident side may be configured to make light incident along the axis of the core portion 14 from the end surface of the core portion 14. At that time, a connector may be attached to the incident end.

  In addition, a plurality of inclined surfaces may be formed in the optical waveguide. For example, when two inclined surfaces are formed, one inclined surface can be used as a light incident side mirror, and the other inclined surface can be used as a light emitting side mirror.

DESCRIPTION OF SYMBOLS 1 Optical waveguide 10 Laminated body 10a Surface 10b Surface 100 Opto-electric hybrid board 11 Cladding layer 12 Cladding layer 13 Core layer 14 Core part 15 Side clad part 170 Notch 171 Inclined surface 172 Inclined surface 172 'Upright surface 176 Reflective film 178 Bottom surface 179 Contour line 179a End part 179b End part 179c Center part 2 Support film 3 Cover film 5 Electric wiring board 50 Multilayer board 51 Core board 52 Build-up layer 521 Insulating layer 522 Conductor layer 53 Through hole 54 Solder resist layer 6 Optical element 60 Element body 61 Light emitting / receiving section 62 Terminal 63 Bump 7 Resin material 9 Opening 90 Adhesive sheet A Axis D Maximum depth G Gap W Maximum width W ₁ width

Claims (9)

A laminated body in which a first cladding layer, a core layer in which a core portion is formed, and a second cladding layer are laminated;
A notch provided with an inclined surface that is formed from the second cladding layer side toward the core portion and is inclined with respect to the axis of the core portion;
The optical waveguide according to claim 1, wherein a contour line on the first clad layer side of the inclined surface is positioned on the first clad layer side with respect to both ends thereof.   The optical waveguide according to claim 1, wherein the contour line is curved in a concave shape.   The optical waveguide according to claim 1, wherein both ends of the contour line are located in the first cladding layer.   The optical waveguide according to claim 1, wherein both ends of the contour line are located in the core layer.   The optical waveguide according to any one of claims 1 to 3, wherein a central portion and an end portion of the contour line are located in different layers of the stacked body.   The optical waveguide according to claim 1, wherein the inclined surface is a curved convex surface.   The optical waveguide according to claim 1, wherein the inclined surface is a flat surface. An optical waveguide according to any one of claims 1 to 7,
An opto-electric hybrid board, comprising: an electric wiring board laminated on the optical waveguide and provided with electric wiring on a surface thereof.   An electronic apparatus comprising the opto-electric hybrid board according to claim 8.