JP2015108647A - Manufacturing method for optical waveguide with lens, optical waveguide with lens, photo-electric hybrid board and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for an optical waveguide with a lens, and an optical waveguide with a lens, a photoelectric hybrid board and electronic equipment, in which a lens can be easily and inexpensively formed and decrease in propagation characteristics of light can be suppressed.SOLUTION: The manufacturing method for an optical waveguide with a lens includes: a lens formation step of forming a lens 8 on an upper face of a layer type optical waveguide 1A including a core and a cladding; and a mirror formation step of forming a notch 70 having a mirror 7 on a lower face of the optical waveguide 1A to correspond to the lens 8. The lens formation step includes: a supply step of supplying a lens material to a mold 200 having a lens mold; a drying step of drying the lens material; and an adhesion step of adhering the lens material as accommodated in the mold 200 to the upper face of the optical waveguide 1A.

Description

  The present invention relates to a method for manufacturing an optical waveguide with a lens, an optical waveguide with a lens, an opto-electric hybrid board, and an electronic device.

  As an optical waveguide capable of realizing optical transmission, one having a core part and a clad part covering the core part is known. A mirror is formed in the middle (both ends) of the core portion, and light from the optical element mounted on the optical waveguide is reflected by the mirror and enters the core portion. The light propagated through the core part is reflected by the mirror and reaches the optical element. An optical waveguide having such a configuration is known in which a lens (coupling lens) that couples them is arranged between a mirror and an optical element (for example, see Patent Document 1).

  Here, in the optical waveguide of Patent Document 1, a lens is formed by patterning the surface of the optical waveguide using laser processing. However, in such a method, there is a problem that the apparatus becomes large and the lens cannot be formed easily and inexpensively.

  In Patent Document 1, the mirror and lens formation areas are set in advance before forming them, and the mirror and lens are processed based on the set conditions. Therefore, when at least one of the mirror and the lens is deviated from a predetermined formation position, there is a problem that the light propagation characteristic is deteriorated.

Japanese Patent No. 4225054

  An object of the present invention is to provide a method of manufacturing an optical waveguide with a lens capable of easily and inexpensively forming a lens and further suppressing a decrease in light propagation characteristics, an optical waveguide with a lens, an opto-electric hybrid board, and To provide electronic equipment.

Such an object is achieved by the present inventions (1) to (10) below.
(1) a lens forming step of forming a lens on one surface of a layered optical waveguide having a core portion and a cladding portion;
A mirror forming step of forming a notch portion having a mirror for converting the optical path of the core portion in correspondence with the lens on the other surface of the optical waveguide;
The lens forming step includes supplying a lens material to a mold having a lens mold;
A drying step of drying the lens material;
And a bonding step of bonding the lens material as it is in the mold to one surface of a layered optical waveguide having a core portion and a cladding portion.

  (2) The manufacturing method of the optical waveguide with a lens as described in said (1) which has the removal process which removes the said type | mold from the said lens material after the said adhesion process.

  (3) The method for manufacturing an optical waveguide with a lens according to the above (1) or (2), which has a curing step of curing the lens material prior to the bonding step.

  (4) In the bonding step, the lens waveguide optical waveguide manufacturing method according to any one of (1) to (3), wherein the lens material is bonded to one surface of the optical waveguide via an adhesive. .

  (5) In the bonding step, the lens material that has been put in the mold is brought into contact with one surface of the optical waveguide, and then the lens material is cured, whereby the lens material is made into the optical waveguide. The manufacturing method of the optical waveguide with a lens as described in said (1) or (2) to adhere | attach.

  (6) The method for manufacturing an optical waveguide with a lens according to any one of (1) to (5), wherein the lens material is the same as a constituent material of the core portion.

  (7) The method for manufacturing an optical waveguide with a lens according to any one of (1) to (5), wherein in the mirror forming step, the mirror is formed using the lens as an alignment mark.

  (8) An optical waveguide with a lens manufactured by the method for manufacturing an optical waveguide with a lens according to any one of (1) to (7).

(9) The optical waveguide with a lens according to (8),
An opto-electric hybrid board, comprising: an electrical wiring board that is laminated on the optical waveguide with a lens and has electrical wiring on a surface thereof.
(10) An electronic apparatus comprising the opto-electric hybrid board according to (9).

  According to the present invention, a lens can be formed easily and inexpensively, and a method for producing a lens-attached optical waveguide that can suppress a decrease in light propagation characteristics is obtained.

Further, according to the present invention, a highly reliable optical waveguide with a lens can be obtained.
Further, according to the present invention, a highly reliable opto-electric hybrid board can be obtained.
In addition, according to the present invention, a highly reliable electronic device can be obtained.

It is a longitudinal cross-sectional view which shows suitable embodiment of the opto-electric hybrid board | substrate of this invention. FIG. 2 is a perspective view showing a part of the optical waveguide shown in FIG. 1 in an enlarged manner (partially cut out and shown through). It is a longitudinal cross-sectional view which shows a mode that the optical element was mounted in the opto-electric hybrid board | substrate shown in FIG. It is sectional drawing which shows the manufacturing method of the optical waveguide with a lens with which the opto-electric hybrid board | substrate shown in FIG. 1 is provided. It is sectional drawing which shows the manufacturing method of the optical waveguide with a lens with which the opto-electric hybrid board | substrate shown in FIG. 1 is provided. It is sectional drawing which shows the manufacturing method of the optical waveguide with a lens with which the opto-electric hybrid board | substrate shown in FIG. 1 is provided. It is sectional drawing which shows the manufacturing method of the optical waveguide with a lens with which the opto-electric hybrid board | substrate shown in FIG. 1 is provided. It is sectional drawing which shows the manufacturing method of the optical waveguide with a lens with which the opto-electric hybrid board | substrate shown in FIG. 1 is provided.

  Hereinafter, the manufacturing method of the optical waveguide with a lens of this invention, the optical waveguide with a lens, an opto-electric hybrid board, and an electronic device are explained in detail based on a suitable embodiment shown in an accompanying drawing.

  FIG. 1 is a longitudinal sectional view showing a preferred embodiment of the opto-electric hybrid board according to the present invention, and FIG. 2 is an enlarged view of a part of the optical waveguide shown in FIG. 3 is a longitudinal sectional view showing a state in which an optical element is mounted on the opto-electric hybrid board shown in FIG. 1, and FIGS. 4 to 8 are respectively provided in the opto-electric hybrid board shown in FIG. It is sectional drawing which shows the manufacturing method of the optical waveguide with a lens.

1. An opto-electric hybrid board 100 shown in FIG. 1 includes an optical waveguide 10 with a lens, an electric wiring board 5 laminated on the upper surface thereof, an adhesive sheet 9 that is interposed between them and bonds them together, have. Hereinafter, the configuration of each part of the opto-electric hybrid board 100 will be sequentially described.

(Optical waveguide with lens)
The lens-equipped optical waveguide 10 is a member that has a layered shape and can transmit an optical signal. As shown in FIG. 2, the lens-attached optical waveguide 10 has an optical waveguide 1 and a lens 8 disposed in the optical waveguide 1.

-Optical waveguide-
The optical waveguide 1 includes a laminate in which a clad layer 11, a core layer 13 and a clad layer 12 are laminated in this order from below, a support film 2 laminated on the lower surface of the laminate, and an upper surface of the laminate. A laminated cover film 3 and a mirror (optical path conversion unit) 7 formed from the lower surface side of the support film 2 to the upper surface of the cladding layer 12 are provided.

  Further, as shown in FIG. 2, the core layer 13 is provided adjacent to each of the plurality of long core portions 14 provided in parallel in a plan view and adjacent to each core portion 14 (that is, the core layer 13 And a side cladding portion 15 having a refractive index lower than that of the core portion 14. Thereby, 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 propagated by the core part 14.

  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 refractive index of the core portion 14 is A and the refractive index of the cladding portion is B.
Refractive index difference (%) = | A / B-1 | × 100

  Further, the refractive index distribution in the cross section of the core portion 14 may be any shape distribution. For example, 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 may be used. 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.

  Note that the GI-type refractive index distribution is a distribution in which the refractive index continuously changes. For example, for the refractive index in the core layer 13, the position in the width direction of the core portion 14 is represented by the horizontal axis, and the refractive index is represented by the refractive index distribution. When taken on the vertical axis, the distribution is preferably a continuous curve having a local maximum near the center of the core portion 14. In the core part 14 having such a refractive index distribution, the optical signal propagates near the center of the core part 14. For this reason, the transmission efficiency is improved as described above. Moreover, when the core parts 14 cross | intersect so that it may mention later, the interference of an optical signal can be suppressed in an intersection part. For this reason, even when the core part 14 is configured to pass through a plurality of intersections, the quality of optical communication is unlikely to deteriorate, so that there is an advantage that the degree of freedom in designing the optical circuit can be particularly increased.

  Furthermore, the continuous curve is preferably a curve having a minimum near the boundary between the core portion 14 and the side cladding portion 15. According to such a refractive index distribution, the refractive index difference between the vicinity of the center of the core portion 14 and the vicinity of the boundary between the side cladding portions 15 is particularly large, and therefore, the action of confining an optical signal near the center of the core portion 14 is particularly large. Be enhanced. As a result, transmission efficiency is particularly high, and interference of optical signals can be particularly suppressed at the intersection.

  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. ), It is possible to efficiently manufacture the core portion 14 with stable quality. Moreover, the planar view shape of the core part 14 is not specifically limited, A straight line or a curve may be sufficient.

  Further, the width and height of the core part 14 (thickness of the core layer 13) are not particularly limited, but are preferably about 1 to 200 μm, more preferably about 5 to 100 μm, More preferably, it is about 70 μm. Thereby, it is possible to increase the density of the core portion 14 while suppressing a decrease in the transmission efficiency of the optical waveguide 1.

  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. Moreover, the number of the core parts 14 is not specifically limited, One may be sufficient and two or more may be sufficient.

  When the plurality of core portions 14 are arranged in parallel, the width of the side clad portion 15 located between the core portions 14 is preferably about 5 to 250 μm, more preferably about 10 to 200 μm, More preferably, it is about 10-120 micrometers. Thereby, it is possible to increase the density of the core portion 14 while preventing the optical signals from being mixed (crosstalk) between the core portions 14.

  Further, in the portion where the plurality of core portions 14 are arranged in parallel, the ratio (WCO / WCL) of the width WCO of the core portion 14 to the width WCL of the side cladding portion is preferably in the range of 0.1-10. , 0.1 to 5 is more preferable, and 0.2 to 4 is more preferable. Thus, by optimizing the ratio of WCO and WCL, it is possible to particularly enhance the reduction in transmission efficiency and the increase in the density of the core unit 14.

  The constituent material (main material) of the core layer 13 as described above is, for example, acrylic resin, methacrylic resin, polycarbonate, polystyrene, cyclic ether resin such as epoxy resin or oxetane resin, polyamide, polyimide, poly Benzoxazole, polysilane, polysilazane, silicone resin, fluorine resin, polyurethane, polyolefin resin, polybutadiene, polyisoprene, polychloroprene, polyester such as PET and PBT, polyethylene succinate, polysulfone, polyether, benzocyclo In addition to various resin materials such as cyclic olefin resins such as butene resin and norbornene resin, glass materials such as quartz glass and borosilicate glass can be used. Note that the resin material may be a composite material in which materials having different compositions are combined.

  Among these, at least one selected from the group consisting of (meth) acrylic resins, epoxy resins, silicone resins, polyimide resins, fluorine resins, and polyolefin resins is particularly preferable. A resin or epoxy resin is more preferable. Since these resin materials have high light transmittance, the optical waveguide 1 with particularly small transmission loss can be obtained.

On the other hand, the clad layers 11 and 12 are located below and above the core layer 13.
The average thickness of the cladding layers 11 and 12 is preferably about 0.05 to 1.5 times the average thickness of the core layer 13, and more preferably about 0.1 to 1.25 times. Specifically, the average thickness of the cladding layers 11 and 12 is preferably about 1 to 200 μm, more preferably about 3 to 100 μm, and further preferably about 5 to 60 μm. Thereby, the function as a clad part is ensured while preventing the optical waveguide 1 from becoming thicker than necessary.

  Further, as the constituent material of the cladding layers 11 and 12, for example, the same material as the constituent material of the core layer 13 described above can be used, and in particular, (meth) acrylic resin, epoxy resin, silicone resin, It is preferably at least one selected from the group consisting of a polyimide resin, a fluorine resin, and a polyolefin resin, and more preferably a (meth) acrylic resin or an epoxy resin.

  Also, the refractive index distribution in the thickness direction of the cross section of the optical waveguide 1 may be SI type or GI type distribution. Among them, the GI type distribution is a distribution composed of a continuous curve having a maximum near the center of the core portion 14 when the position in the thickness direction of the optical waveguide 1 is taken on the vertical axis and the refractive index is taken on the horizontal axis. Is preferred. Furthermore, the continuous curve is preferably a curve having a minimum near the boundary between the core portion 14 and the cladding layers 11 and 12. According to the refractive index distribution composed of such a curve, the transmission efficiency of the optical waveguide 1 is particularly high, and interference of optical signals can be particularly suppressed at the intersection.

  Moreover, as shown in FIG. 1, the support film 2 may be provided in the lower surface of the optical waveguide 1, and the cover film 3 may be provided in the upper surface, respectively. In addition, these should just be provided as needed and can also be abbreviate | omitted.

  Examples of the constituent material of the support film 2 and the cover film 3 include various resin materials such as polyethylene terephthalate (PET), polyolefin such as polyethylene and polypropylene, polyimide, and polyamide.

  Moreover, although the average thickness of the support film 2 and the cover film 3 is not specifically limited, It is preferable that it is about 5-500 micrometers, and it is more preferable that it is about 10-400 micrometers. Thereby, the core layer 13 and the clad layers 11 and 12 can be reliably protected from an external force or an external environment.

  Further, in the optical waveguide 1 shown in FIG. 1, a cavity (notch) 70 is formed from the lower surface side of the support film 2 to the upper surface of the cladding layer 12. And the area | region which crosses the core part 14 among the inner surfaces of this cavity part 70 becomes the mirror (optical path conversion part) 7 which converts the optical path of the core part 14. FIG.

  The cavity 70 is formed by digging or the like from the lower surface of the support film 2, and in the case of FIG. 1, the vertical cross-sectional shape is a triangle. The mirror 7 is a plane that obliquely crosses the middle of the core portion 14 and is inclined by 45 ° with respect to the optical axis of the core portion 14. Therefore, the light propagating through the core portion 14 is reflected by the mirror 7 and its optical path is converted 90 ° upward. Further, the light propagating from above in FIG. 1 is reflected by the mirror 7 and enters the core portion 14.

  The angle formed by the mirror 7 and the optical axis of the core portion 14 is not limited to the 45 ° described above, and may be any angle that allows the optical path of the core portion 14 to be converted and optically connected to the outside of the optical waveguide 1. . For example, it is preferably about 30 to 60 °, and more preferably about 42 to 47 °.

  In addition, a reflective film may be formed on the inner surface of the cavity 70 as necessary. Examples of the reflective film include a metal film such as Au, Ag, and Al, and a film made of a material having a lower refractive index than the core portion 14. Examples of the metal film forming method include physical vapor deposition such as vacuum vapor deposition, chemical vapor deposition such as CVD, and plating.

  Further, the mirror 7 may be provided not in the middle of the core part 14 but in the side clad part 15 and on an extension line of the core part 14.

  The hollow portion 70 may be filled with some material as necessary. In this case, the refractive index of the material to be filled is preferably smaller than the refractive index of the core portion 14.

  Further, the mirror 7 can be replaced by an optical path conversion unit having another structure such as a curved waveguide.

-Lens-
As shown in FIG. 1, the upper surface of the optical waveguide 1 is formed on the mirror 7. By providing the lens 8, the light reflected by the mirror 7 from the core portion can be efficiently guided to the optical element 6.

  The material of the lens 8 is not particularly limited as long as the function described above can be exhibited. For example, a cyclic ether resin such as an acrylic resin, a methacrylic resin, a polycarbonate, a polystyrene, an epoxy resin, or an 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 In addition to various resin materials such as ether and cyclic olefin resins such as benzocyclobutene resins and norbornene resins, glass materials such as quartz glass and borosilicate glass can be used. . Note that the resin material may be a composite material in which materials having different compositions are combined. Among these, as the constituent material of the lens 8, it is preferable to use the same material as the constituent material (main material) of the core layer 13 described above. By using the same material, the cost of forming the lens 8 can be reduced.

(Electric wiring board)
1 is an interposer in which insulating layers 521 and 523 are stacked, and a conductor layer 522 is provided between the insulating layers 521 and 523 and can be electrically connected to other circuits via the vias 16. Used as

  Examples of the constituent material of the electrical wiring board 5 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 a base material, and this base material is impregnated with a resin material such as a phenol resin, a polyester resin, an epoxy resin, a cyanate resin, a polyimide resin, or a fluorine resin. In addition to insulating substrates used for composite copper-clad laminates such as glass cloth / epoxy copper-clad laminates, glass nonwoven fabrics / epoxy copper-clad laminates, polyetherimide resin substrates, polyethers It may be a heat-resistant / thermoplastic organic rigid substrate such as a ketone resin substrate or a polysulfone resin substrate, or a ceramic rigid substrate such as an alumina substrate, an aluminum nitride 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. 1 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.

  The solder resist layer 54 is made of various resin materials and includes an inorganic filler as necessary. The average thickness of the solder resist layer 54 is not particularly limited, but is preferably about 5 to 100 μm, more preferably about 10 to 50 μm, and still more preferably about 20 to 40 μm. By setting the thickness of the solder resist layer 54 within the above range, the conductor resist 522 is protected and the upper surface of the electric wiring board 5 is smoothed, and sufficient light transmittance of the solder resist layer 54 is ensured. Can do.

  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.

(Adhesive sheet)
The adhesive sheet 9 is a sheet mainly composed of a thermosetting resin, and adheres the electric wiring substrate 5 and the optical waveguide 1 by curing.

  The material constituting the adhesive sheet 9 is mainly composed of a thermosetting resin, for example. Specifically, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol type epoxy resin such as bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. In addition to various epoxy resins such as novolak epoxy resin, aromatic epoxy resin such as trisphenolmethane triglycidyl ether, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, imide resin such as polyimide and polyamideimide, silicone Resins, phenol resins, urea resins and the like can be mentioned, and one or more of these can be used in combination.

  The constituent material of the adhesive sheet 9 is acrylonitrile-butadiene rubber (NBR), reactive terminal carboxyl group NBR (CTBN), styrene-butadiene rubber (SBR), polybutadiene, acrylic rubber, in addition to the above thermosetting resin. Such a rubber component as above, a vinyl acetate resin, a polyvinyl alcohol resin, a polyvinyl acetal resin, an acrylic resin, a polyacrylonitrile resin, a vinyl urethane resin, a polyester resin, and a thermoplastic resin such as a polyamide resin may be contained. The content of these rubber components and the thermoplastic resin is preferably about 10 to 200 parts by mass, more preferably about 20 to 150 parts by mass with respect to 100 parts by mass of the thermosetting resin.

  Furthermore, the constituent material of the adhesive sheet 9 may contain additives such as various curing agents such as amine-based curing agents and phenol-based curing agents, curing accelerators, silane coupling agents, and fillers as necessary. Good. The content of these additives is preferably about 0.05 to 50 parts by mass and more preferably about 0.1 to 30 parts by mass with respect to 100 parts by mass of the thermosetting resin.

(Optical element)
Furthermore, the opto-electric hybrid board of the present invention may have an optical element 6 mounted on an electric wiring board 5 as shown in FIG.

  The optical element 6 shown in FIG. 3 has bumps 63 provided so as to protrude downward, and the periphery of the bumps 63 is covered with an underfill 60.

  The optical element 6 is disposed so that the optical axis of the light emitting / receiving unit 61 coincides with the optical axis of the core unit 14 via the mirror 7. 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).
The configuration of the opto-electric hybrid board has been described above.

2. Manufacturing Method of Optical Waveguide with Lens 10 Next, a manufacturing method of the optical waveguide with lens 10 will be described.

  The manufacturing method of the optical waveguide with lens 10 includes a lens forming step of forming the lens 8 on one surface of the layered optical waveguide 1A including the core portion 14 and the clad portion (the clad layer 11, the clad layer 12, and the side clad portion 15). And a mirror forming step of forming a notch portion 70 having a mirror 7 that converts the optical path of the core portion 14 in correspondence with the lens 8 on the other surface of the optical waveguide 1A.

(Lens formation process)
The lens forming process includes a supplying process for supplying the lens material 81 to the mold 200 having the lens mold 210, a drying process for drying the lens material 81, a curing process for curing the lens material 81, and one surface of the optical waveguide 1A. There are a bonding step of bonding the lens material 81 as it is in the mold 200 and a detaching step of removing the mold 200 from the lens material 81 (lens 8).

  Prior to describing each step, an example of a method for manufacturing the optical waveguide 1A will be described. First, as shown in FIG. 4A, the support film 2 is prepared, and the cladding layer 11 is formed on the prepared support film 2. Specifically, first, the resin composition for forming a clad layer is uniformly applied onto the support film 2 by a doctor blade. Next, the resin composition for forming a cladding layer is dried to remove the solvent. Next, the resin composition for forming a cladding layer is cured. Thereby, the clad layer 11 is formed.

  Next, as shown in FIG. 4B, the core layer 13 is formed on the clad layer 11. Specifically, first, the photosensitive resin composition is uniformly coated on the clad layer 11 with a doctor blade. Next, the photosensitive resin composition is dried to remove the solvent to form a film. Next, after the pattern is irradiated (exposed) with ultraviolet rays on the obtained film, the film is cured. Thereby, the core layer 13 in which the core part 14 and the side clad part 15 are formed corresponding to the irradiation pattern of the ultraviolet rays is formed. Depending on the material of the photosensitive resin composition, the portion irradiated with ultraviolet rays becomes the side cladding portion 15, and the portion not irradiated with ultraviolet rays becomes the core portion 14. Conversely, the portion irradiated with ultraviolet rays becomes the core portion 14. In some cases, the portion not irradiated with ultraviolet rays becomes the side cladding portion 15.

  Next, as shown in FIG. 4C, the cladding layer 12 is formed on the core layer 13 in the same manner as the formation of the cladding layer 11. Next, the cover film 3 is disposed on the cladding layer 12. As described above, the optical waveguide 1 </ b> A in which the cutout portion 70 (mirror 7) is not formed is obtained.

-Supply process-
First, as shown in FIG. 5A, a mold 200 is prepared. In the mold 200, a lens mold 210 corresponding to the surface shape of the lens 8 is formed. Further, for example, when at least one of the lens material 81 and the adhesive 300 described later is an ultraviolet curable resin, the mold 200 may be configured to have ultraviolet transparency.

  The constituent material of the mold 200 is not particularly limited as long as it is hard enough to maintain the shape of the lens mold 210, and various metal materials and various resin materials can be used. Examples of the metal material include various metals such as iron, nickel, copper, aluminum, lead, tin, titanium, and tungsten, or an alloy (for example, stainless steel) or an intermetallic compound containing at least one of these metals, These include oxides, nitrides and carbides of these metals. On the other hand, as the resin material, for example, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl chloride, polystyrene, polyamide, polyimide, polycarbonate, acrylic resin, acrylonitrile-butadiene-styrene copolymer (ABS resin) ), Acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyester such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether, polyether ketone (PEK), polyether ether ketone (PEEK), polyetherimide, polyacetal (POM), etc., or copolymers, blends, polymer alloys, etc. mainly comprising these, and one or more of these In combination it can be used.

  Next, as shown in FIG. 5B, a lens material 81 dissolved in a solvent (solvent) is supplied to the mold 200. As the lens material 81, the materials described above can be used. Among these, as the lens material 81, it is particularly preferable to use the same material as the constituent material of the core layer 13. Thereby, since the material of the core layer 13 and the lens 8 can be used, manufacturing cost can be held down. Further, as the lens material 81, a material having a glass transition temperature higher than that of the constituent material of the core layer 13 is preferably used. Thereby, when forming the notch part 70 by imprint processing or laser processing so that it may mention later, damage (thermal deformation etc.) of the lens 8 can be suppressed effectively.

  The solvent is not particularly limited, and for example, diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether ( Diglyme), ether solvents such as diethylene glycol ethyl ether (carbitol), cellosolve solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane, cyclohexane, toluene, xylene, Aromatic hydrocarbon solvents such as benzene and mesitylene, aromatic heterocyclic compound solvents such as pyridine, pyrazine, furan, pyrrole, thiophene and methylpyrrolidone, N, N-dimethyl Amide solvents such as formamide (DMF) and N, N-dimethylacetamide (DMA), halogen compound solvents such as dichloromethane, chloroform and 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate and ethyl formate , Various organic solvents such as sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane, or mixed solvents containing them.

  The lens material 81 may contain additives such as various curing agents such as amine-based curing agents and phenol-based curing agents, and curing accelerators as necessary. Further, after supplying the lens material 81 to the mold 200, the surface of the lens material 81 (upper surface in FIG. 5B) may be flattened using a blade or the like, if necessary. By flattening, the optical characteristics of the obtained lens 8 are improved.

-Drying process-
Next, the lens material 81 is dried at a temperature and time at which the solvent volatilizes to remove the solvent.

-Curing process-
Next, the lens material 81 is cured. For example, if the lens material 81 is a thermosetting resin, it is cured by heating, and if the lens material 81 is an ultraviolet curable resin (photocurable resin), it is cured by irradiating with ultraviolet rays (light). As a result, the lens material 81 is cured in a surface shape corresponding to the lens mold 210, and the lens 8 is obtained as shown in FIG.

  For example, when a room temperature curable resin that cures at room temperature is used as the lens material 81, this step may be omitted.

-Adhesion process-
Next, as shown in FIG. 6 (a), the lens 8 kept in the mold 200 is placed at a predetermined position on the upper surface (one surface) of the optical waveguide 1A (the optical element 6 and the mirror 7 to be disposed and formed later) Are joined to each other). The bonding method of the lens 8 is not particularly limited, but the adhesive 300 is used in the present embodiment. Thereby, the lens 8 can be firmly joined to the optical waveguide 1A, and the reliability is improved. The adhesive 300 may be applied to the lens 8, may be applied to the optical waveguide 1A, or may be applied to both. Further, the adhesive 300 is not particularly limited as long as it has light transmissivity, and for example, various adhesives such as epoxy and acrylic can be used. Moreover, you may use an adhesive sheet. The adhesive sheet is not particularly limited as long as it has optical transparency. For example, the same adhesive sheet as that described above can be used. The light coupling efficiency of the lens 8 is optimized by optimizing the thickness of the adhesive 300 (the adhesive sheet) and the thickness of the lens material 81 according to the shape of the lens 8 and the position where the optical element 6 is disposed. Can be increased.

  In the bonding step, the lens 8 is bonded to the optical waveguide 1 while being placed in the mold 200, whereby the strength of the lens 8 can be increased and the lens 8 can be prevented from being damaged during this step. Further, since the mold 200 functions as a handling member, this process can be performed smoothly. Further, since the mold 200 also functions as a protective member that protects the lens surface of the lens 8, damage to the lens surface during this process is prevented.

-Removal process-
Next, as shown in FIG. 6B, the mold 200 is removed from the lens 8 (lens material 81). Thereby, the lens 8 is exposed on the optical waveguide 1A, and the optical element 6 can be disposed. Note that this step may be omitted. That is, the manufacturer may ship (sale, etc.) while the mold 200 is attached to the lens 8, or may place the optical element 6 by removing the mold 200 at the supplier. . Thereby, since the mold 200 functions as a protective member for the lens 8, it is possible to effectively prevent the lens 8 from being damaged during conveyance.

  The lens forming process has been described above. According to such a process, the lens 8 can be formed easily and inexpensively. Specifically, since the lens 8 can be formed simply by bonding the lens material 81 placed in the mold 200 to the optical waveguide 1A, the lens 8 can be formed more easily than in the case of conventional laser processing. . In addition, since the mold 200 can be reused without using a special apparatus such as laser processing, the lens 8 can be formed at low cost.

  The mold 200 is formed with a plurality of lens molds 210, and the plurality of lenses 8 may be simultaneously formed on the optical waveguide 1A. Thereby, the time required for the formation process of the lens 8 can be shortened.

(Mirror formation process)
Next, as shown in FIG. 6C, a notch 70 (mirror 7) is formed on the lower surface of the optical waveguide 1A on which the lens 8 is formed (the other surface, the surface opposite to the surface on which the lens 8 is formed). Form. At this time, by forming the cutout portion 70 using the lens 8 as an alignment mark, the cutout portion 70 can be formed with high positional accuracy. In particular, the cutout portion 70 is formed corresponding to the lens 8, that is, so as to overlap the lens 8 and the optical waveguide 1 </ b> A in the thickness direction. The cutout portion 70 can be formed with high accuracy. Further, even if the arrangement of the lens 8 is deviated from a predetermined position, the notch 70 can be formed corresponding to the deviated lens 8, so that the lens 8 is arranged behind the mirror 7. The optical element 6 can be reliably coupled.

  A method for forming the cutout portion 70 is not particularly limited, and for example, imprint processing, dicing processing, laser processing, and the like can be suitably used.

  As shown in FIG. 7A, the imprint process is a process of forming the cutout portion 70 by hot pressing with a tapered die 400 corresponding to the shape of the cutout portion 70 from the lower surface side of the optical waveguide 1A. Is the method. According to such a processing method, the cutout portion 70 can be formed more easily.

  For example, as shown in FIG. 7B, the dicing process is a processing method in which a notched part 70 is formed by cutting the lower surface of the optical waveguide 1 </ b> A using a dicing saw 500 having a tapered blade part 510. is there. Also by such a processing method, the cutout portion 70 can be formed more easily. In addition, after the cutting by the dicing saw 500 is completed, the mirror 7 may be polished (polished) as necessary.

  Laser processing is a processing method for forming the cutout portion 70 by irradiating the laser beam LL from the lower surface side of the optical waveguide 1A as shown in FIG. In such a processing method, for example, by using a mask or the like that blocks the irradiation of the laser LL, the accumulated irradiation amount of the laser LL is gradually increased from the left side to the right side in FIG. A notch 70 can be formed. Also by such a processing method, the cutout portion 70 can be formed more easily.

  In imprint processing and laser processing, excessive heat may be transmitted to the lens 8. Therefore, as described above, the lens material 81 is made of a material having a glass transition temperature higher than that of the constituent material of the core layer 13, whereby thermal damage to the lens 8 can be effectively suppressed.

  The optical waveguide 10 with a lens is obtained by the above. According to such a manufacturing method, a lens can be formed easily and inexpensively, and the relative positional relationship between the lens 8 and the mirror 7 can be set to a predetermined value. An optical waveguide with a lens 10 that can suppress the above is obtained. In addition, you may implement the removal process mentioned above after a mirror formation process.

  Moreover, as a lens formation process included in the manufacturing method of the optical waveguide 10 with a lens, the following processes may be sufficient, for example.

(Lens formation process)
The forming process of another lens 8 includes a supplying process of supplying the lens material 81 to the mold 200 having the lens mold 210, a drying process of drying the lens material 81, and a mold 200 on the upper surface (one surface) of the optical waveguide 1A. The lens material 81 as it is, and the step of removing the mold 200 from the lens material 81 (lens 8).

-Supply process-
Since this step is the same as the lens forming step described above, the description thereof is omitted.

-Drying process-
Since this step is the same as the lens forming step described above, the description thereof is omitted.

-Joining process-
First, as shown in FIG. 8A, the lens material 81 that is still in the mold 200 is placed (contacted) at a predetermined position on the upper surface of the optical waveguide 1A. Next, as shown in FIG. 8B, the lens 8 is formed by curing the lens material 81. Thus, by hardening the lens material 81 on the optical waveguide 1, the lens 8 can be formed and the lens 8 can be bonded to the optical waveguide 1A. The curing method is the same as the method described in the lens forming step described above. According to such a method, for example, the lens 8 can be bonded to the optical waveguide 1A without using the adhesive 300 as in the lens forming step described above, and the number of members can be reduced and the cost can be reduced. Can do. Further, the protruding height of the lens 8 can be suppressed by the thickness of the adhesive 300.

-Removal process-
Since this step is the same as the lens forming step described above, the description thereof is omitted. This step may be omitted in the same manner as the lens forming step described above.

  Also by such a process, the lens 8 can be formed easily and inexpensively as in the lens forming process described above. In this formation step, the lens material 81 that is still in the mold 200 is placed on the optical waveguide 1A, and then the lens material 81 is cured while being in the mold 200 to obtain the lens 8. After removing 200, the lens material 81 may be cured to obtain the lens 8. Further, although the lens 8 is directly bonded to the optical waveguide 1A, the lens 8 (lens material 81) may be bonded to the optical waveguide 1A via the adhesive 300.

<Electronic equipment>
As described above, the opto-electric hybrid board of the present invention as described above can easily perform accurate processing on the optical waveguide with reference to the electrical wiring board. In the case of mounting, the optical element and the electric wiring board can be reliably connected without causing an increase in conduction resistance or disconnection. As a result, a highly reliable optical module can be manufactured efficiently. In addition, by providing such an opto-electric hybrid board, a highly reliable electronic device that can perform high-quality optical communication can be obtained.

  Examples of the electronic device provided with the opto-electric hybrid board 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, by providing such an electronic device with the opto-electric hybrid board of the present invention, problems such as noise and signal degradation peculiar to the electrical wiring are eliminated, and a dramatic improvement in performance can be expected.

  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.

  As mentioned above, although the manufacturing method of the optical waveguide with a lens of this invention, the optical waveguide with a lens, an opto-electric hybrid board, and an electronic device were demonstrated based on embodiment of illustration, this invention is not limited to these.

DESCRIPTION OF SYMBOLS 1, 1A optical waveguide 10 Optical waveguide with lens 100 Opto-electric hybrid board 11 Clad layer 12 Clad layer 13 Core layer 14 Core part 15 Side clad part 16 Via 2 Support film 200 type 210 Lens type 3 Cover film 300 Adhesive 400 type 5 Electrical wiring substrate 500 Dicing saw 510 Blade portion 521 Insulating layer 522 Conductive layer 523 Insulating layer 53 Bump 54 Solder resist layer 6 Optical element 60 Underfill 63 Bump 7 Mirror 70 Cavity 8 Lens 81 Lens material 9 Adhesive sheet

Claims (10)

A lens forming step of forming a lens on one surface of a layered optical waveguide having a core portion and a cladding portion;
A mirror forming step of forming a notch portion having a mirror for converting the optical path of the core portion in correspondence with the lens on the other surface of the optical waveguide;
The lens forming step includes supplying a lens material to a mold having a lens mold;
A drying step of drying the lens material;
And a bonding step of bonding the lens material as it is in the mold to one surface of a layered optical waveguide having a core portion and a cladding portion.   The manufacturing method of the optical waveguide with a lens of Claim 1 which has the removal process which removes the said type | mold from the said lens material after the said adhesion process.   The manufacturing method of the optical waveguide with a lens according to claim 1 or 2 which has a hardening process which hardens said lens material prior to said adhesion process.   The method for manufacturing an optical waveguide with a lens according to any one of claims 1 to 3, wherein in the bonding step, the lens material is bonded to one surface of the optical waveguide through an adhesive.   In the bonding step, the lens material is bonded to the optical waveguide by curing the lens material after bringing the lens material that is still in the mold into contact with one surface of the optical waveguide. Item 3. A method for producing an optical waveguide with a lens according to Item 1 or 2.   The method for manufacturing an optical waveguide with a lens according to claim 1, wherein the lens material is the same as a constituent material of the core portion.   The method for manufacturing an optical waveguide with a lens according to claim 1, wherein in the mirror forming step, the mirror is formed using the lens as an alignment mark.   An optical waveguide with a lens manufactured by the method for manufacturing an optical waveguide with a lens according to any one of claims 1 to 7. An optical waveguide with a lens according to claim 8,
An opto-electric hybrid board, comprising: an electrical wiring board that is laminated on the optical waveguide with a lens and has electrical wiring on a surface thereof.   An electronic apparatus comprising the opto-electric hybrid board according to claim 9.

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