JP3794331B2 - Manufacturing method of optical waveguide - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to a method of manufacturing an optical waveguide used for optical interconnection and the like.
[0002]
[Prior art]
In recent years, the superiority of light has been demonstrated by the progress of optical communication technology. In addition, with the speeding up of signals of LSIs and the like, research and development of techniques for replacing electrical signals with optical signals are being carried out. An optical waveguide is expected as the transmission medium.
[0003]
Polymer optical waveguides that have been developed in recent years can be formed in a large area, and are applied to optical interconnections on the order of 1 cm to 1 m. Also, an optical component is mounted on the surface of a waveguide layer by forming an optical path conversion mirror on the optical waveguide.
[0004]
As a method for producing a polymer optical waveguide, a method using dry etching (FIG. 10) and a method using pattern exposure & development (FIG. 11) are generally used. Further, as a method for forming the optical path conversion mirror, machining by a dicing saw (FIG. 12) is generally used.
[0005]
However, separately performing the manufacture of the waveguide and the processing of the optical path conversion mirror results in a complicated manufacturing process and high cost. Therefore, there is a method using a mold (FIG. 13, Japanese Patent Application Laid-Open No. 2001-332870) as a method for simultaneously producing a waveguide and a mirror. Here, the core 1 is applied on the substrate 10 having the recesses, the cores 1 other than the recesses are removed, the clad 2 is formed on the entire surface, the whole is transferred to another substrate 20, and then the clad 3 is formed on the entire surface. ing.
[0006]
However, removing the core 1 other than the recesses after applying the core 1 to the entire surface of the substrate 10 having the recesses deteriorates the use efficiency of the core material and increases the cost. Further, in order to transfer the clad 2 to the other substrate 20 after forming the clad 2 on the entire surface of the substrate 10 having the recesses, an adhesive 56 is required and the process is complicated.
[0007]
[Problems to be solved by the invention]
The present invention has been made in view of the state of the related art, and an object of the present invention is to provide an easy waveguide manufacturing method that does not require the use of a new adhesive during transfer. It is another object of the present invention to provide an inexpensive waveguide manufacturing method with good use efficiency of the core material.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, first, the invention of claim 1 is a method of manufacturing an optical waveguide comprising a core and a clad, wherein only the concave portion of the substrate is slightly raised from the surface of the concave portion, and the core material is filled and cured. Forming a core , applying a clad material to another substrate and curing to produce a clad substrate, transferring the core to the clad substrate, and further covering with a clad, at least seen including a core material and the cladding material is a resin, in which at least one of the curing steps and a cladding material for curing the core material is a manufacturing method of the optical waveguide, which is a semi-cured is there.
[0009]
The invention of claim 2 is a method of manufacturing an optical waveguide comprising a core and a clad, wherein the core material is filled only in the concave portion of the substrate and cured below the concave surface, and the concave portion is formed in the remaining portion of the concave portion. Slightly raised from the surface, filled with the first clad material and cured to produce the core and the first clad, and coated and cured with the second clad material on another substrate, with the second clad Including at least a step of manufacturing a substrate, a step of transferring the core and the first clad to the second clad substrate, and a step of covering the core with the third clad. The clad material is a resin, and at least one of the step of curing the first clad material and the step of curing the second clad material is semi-cured. .
[0010]
According to a third aspect of the present invention, there is provided the optical waveguide manufacturing method according to the first or second aspect, wherein the semi-cured core material or clad material is completely cured during or after the transfer step.
[0011]
According to a fourth aspect of the present invention, there is provided an optical waveguide manufacturing method according to any one of the first to third aspects, wherein an ink jet printer or a dispenser is used in the step of filling only the recesses of the substrate with the core material or the clad material. It is.
[0012]
According to a fifth aspect of the present invention, there is provided the optical waveguide manufacturing method according to the first to fourth aspects, wherein at least one of the core material and the clad material is an ultraviolet curable epoxy resin.
[0013]
According to a sixth aspect of the present invention, there is provided the method for producing an optical waveguide according to any one of the first to fifth aspects, wherein the concave portion of the substrate has a portion serving as a mold of an optical path conversion mirror.
[0014]
According to a seventh aspect of the present invention, there is provided the method for producing an optical waveguide according to any one of the first to sixth aspects, wherein at least the surface of the substrate having the concave portion is a silicone resin.
[0015]
The invention according to claim 8 is the production of an optical waveguide according to any one of claims 1 to 7, wherein the substrate having the recesses is obtained by applying a liquid resin to the substrate having the projections and then curing the resin. It is a method.
[0016]
The invention according to claim 9 is the method for producing an optical waveguide according to claim 8, wherein the substrate having the convex portion is formed by forming a pattern of a photoresist or an ultraviolet curable epoxy resin on the substrate. It is a thing.
[0017]
The invention of claim 10, the substrate having the projecting portion, the mold type and made part of the optical path conversion mirror, or a substrate having the recess, the mold and becomes part of the optical path conversion mirror, obliquely applied excimer laser 10. The method of manufacturing an optical waveguide according to claim 8, wherein the optical waveguide is processed by:
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail below.
[0019]
First, a substrate 10 having a recess is prepared (FIG. 1A). Not only the core pattern of the waveguide but also a portion corresponding to a mirror or an optical circuit such as a diffraction grating, a branch circuit, or an AWG can be incorporated in the recess.
[0020]
Next, only the concave portion is filled with the core material 1 (FIGS. 1B to 1C). The core material 1 is preferably an ultraviolet curable epoxy resin. As a filling method, an ink jet printer or a dispenser 11 is suitable. As the filling shape, it is more preferable that the core material has the same or slightly raised shape as the concave surface (FIG. 3).
[0021]
The conventional method of shaving by ashing after coating the entire surface is inefficient in use of the material, and the method of scraping with a doctor blade has a problem of dust contamination. More problematic is the state at the time of filling. In ashing, taking over the fact that the surface of the mold part is low at the time of the entire surface application, the core material 1 can be filled only in a shape slightly lower than the surface of the concave part due to adhesion to the blade in the doctor blade (FIG. 4).
[0022]
Other materials such as PMMA and polyimide can be used as the core material 1. When the coating solution contains a solvent, the surface of the core material 1 after curing is lower than the surface of the concave portion, but this can be dealt with by filling the remaining portion with the ultraviolet curable epoxy of the clad material 2 ′ and raising the concave portion (see FIG. 5).
[0023]
Now, another substrate 20 is prepared, and the clad 2 is applied to the entire surface (FIG. 1 (d)). The clad 2 is also preferably an ultraviolet curable epoxy resin. When the core 1 is an ultraviolet curable epoxy resin, the clad 2 may be made of a material other than the ultraviolet curable epoxy resin such as polyimide.
[0024]
The core material 1 of the recess and the clad 2 on the separate substrate 20 are cured. This is for shape stability. However, at least one of them is kept in a semi-cured state and the adhesiveness is left. In the case of an ultraviolet curable resin, it can be realized by a small amount of ultraviolet irradiation.
[0025]
Then, the substrate 10 having the core material 1 and the separate substrate 20 having the clad 2 are overlapped (FIG. 1E), and the core material 1 is transferred to the separate substrate 20 side. At this time, it is preferable to completely cure by irradiating with ultraviolet rays in a superposed state, but it may be cured after transfer. Since the core material 1 is slightly raised and filled from the concave portion, the adhesiveness between the core 1 and the clad 2 is good, and transfer failure hardly occurs.
[0026]
When a waveguide including a mirror is manufactured, a metal is deposited on the mirror surface to form a metal mirror 4 (FIG. 1 (f)). In order to attach metal only to the mirror surface, a mask vapor deposition method or a lift-off method can be used. The optical path conversion mirror can be used not only for optical path conversion in a direction perpendicular to the waveguide layer (FIG. 6), but also for optical path conversion at an arbitrary angle within the waveguide layer (FIG. 7). .
[0027]
Thereafter, the clad 3 is formed on the entire surface, thereby completing the single-layer waveguide 5 (FIG. 1 (g)). Furthermore, the multilayer waveguide 6 can also be formed by filling and transferring the core material 1 ′ to the substrate 10 ′ having another recess (FIG. 2).
[0028]
Note that when forming the multilayer waveguide 6 or for aligning and transferring the waveguides 5 and 6 to another substrate (for example, an electrical wiring substrate: not shown), an alignment mark is formed on another substrate 20 or in the clad 2. It is desirable to provide (not shown). The separate substrate 20 to which the clad 2 is applied is desirably transparent, and it is desirable to provide a transparent release layer (not shown) between the separate substrate 20 and the clad 2.
[0029]
For manufacturing the substrate 10 having the recesses, a method can be used in which the substrate 30 having the protrusions is prepared and molded with the silicone resin 34 or the like (FIGS. 8C to 8D).
[0030]
In manufacturing the substrate 30 having the convex portion, a photoresist or an ultraviolet curable epoxy resin 32 is applied on the substrate 31, and pattern exposure / development is performed in a waveguide shape (FIG. 8A), and the mirror portion is formed. This can be realized by processing with the laser beam 33 (FIG. 8B). As the laser beam 33, an excimer laser is suitable.
[0031]
Alternatively, the substrate 40 having the recesses is coated with a photoresist 42 on the substrate 41 and subjected to pattern exposure / development in a waveguide shape (FIG. 9A), and the mirror portion is processed with the laser beam 43 ( 9 (b) to (c)).
[0032]
【Example】
Example 1
[Substrate with recesses]
An embodiment of the present invention will be described with reference to FIG. First, by applying, baking, exposing, and developing a plating photoresist on the substrate 31 (glass), a waveguide-shaped convex pattern having a cross section of 40 μm square was formed as the resist pattern 32 (FIG. 8A). .
[0033]
Next, by obliquely irradiating a KrF excimer laser as the laser beam 33, a portion to be a mirror was processed (FIG. 8B), and a substrate 30 having a convex portion was formed (FIG. 8C).
[0034]
And the board | substrate 10 which has a recessed part was produced by taking a mold using the liquid silicone resin 34. FIG.
[0035]
(Example 2)
[Optical waveguide 1]
An embodiment of the present invention will be described with reference to FIG. First, according to Example 1, a substrate 10 (silicone resin) having a concave portion was prepared (FIG. 1A). Next, an ultraviolet curable epoxy resin as the core material 1 was filled in the concave portion with the ink jet printer 11 (FIGS. 1B to 1C). At that time, the core material had a shape slightly raised from the concave surface. The core 1 was completely cured by irradiating the entire surface with 1 J / cm ² of ultraviolet rays.
[0036]
On the other hand, another substrate 20 (glass) was prepared, and the entire surface was spin-coated with an ultraviolet curable epoxy resin as the clad material 2 (FIG. 1 (d)). The clad 2 was semi-cured by irradiating the entire surface with ultraviolet rays of 100 mJ / cm ² .
[0037]
Here, in a state where the two were superposed, the core 1 and the clad 2 were adhered and the clad 2 was completely cured by irradiating ultraviolet rays of 1 J / cm ² from another substrate side (FIG. 1 (e)).
[0038]
After peeling off the substrate 10 having the recess, metal mirror 4 was obtained by vapor-depositing metal Al on the mirror surface by mask vapor deposition. Further, an ultraviolet curable epoxy resin was applied to the entire surface as the clad 3 and irradiated with ultraviolet rays to complete the waveguide layer 5.
[0039]
Example 3
[Optical waveguide 2]
Another embodiment of the present invention will be described with reference to FIG. First, according to Example 1, a substrate 10 (silicone resin) having a concave portion was prepared (FIG. 1A). Next, an ultraviolet curable epoxy resin as the core material 1 was filled in the concave portion with the ink jet printer 11 (FIGS. 1B to 1C). At that time, the core material had a shape slightly raised from the concave surface. The core 1 was semi-cured by irradiating the entire surface with 100 mJ / cm ² of ultraviolet rays.
[0040]
On the other hand, another substrate 20 (glass) was prepared, and the entire surface was spin-coated with an ultraviolet curable epoxy resin as the clad material 2 (FIG. 1 (d)). The clad 2 was completely cured by irradiating the entire surface with 1 J / cm ² of ultraviolet rays.
[0041]
In this state, the core 1 and the clad 2 were adhered to each other and the core 1 was completely cured by irradiating ultraviolet rays of 1 J / cm ² from the side of another substrate in a state where they were superposed (FIG. 1 (e)).
[0042]
After peeling off the substrate 10 having the recess, metal mirror 4 was obtained by vapor-depositing metal Al on the mirror surface by mask vapor deposition. Further, an ultraviolet curable epoxy resin was applied to the entire surface as the clad 3 and irradiated with ultraviolet rays to complete the waveguide layer 5.
(Example 4)
[Optical waveguide 3]
Another embodiment of the present invention will be described with reference to FIG. First, according to Example 1, a substrate 10 (silicone resin) having a concave portion was prepared (FIG. 1A). Next, an ultraviolet curable epoxy resin as the core material 1 was filled in the concave portion with the ink jet printer 11 (FIGS. 1B to 1C). At that time, the core material had a shape slightly raised from the concave surface. The core 1 was semi-cured by irradiating the entire surface with 100 mJ / cm ² of ultraviolet rays.
[0043]
On the other hand, another substrate 20 (glass) was prepared, a polyamide solution was spin-coated on the entire surface, and heated to form polyimide as the clad material 2 (FIG. 1D).
[0044]
In this state, the core 1 and the clad 2 were adhered to each other and the core 1 was completely cured by irradiating ultraviolet rays of 1 J / cm ² from the side of another substrate in a state where they were superposed (FIG. 1 (e)).
[0045]
After peeling off the substrate 10 having the recess, metal mirror 4 was obtained by vapor-depositing metal Al on the mirror surface by mask vapor deposition. Further, an ultraviolet curable epoxy resin was applied to the entire surface as the clad 3 and irradiated with ultraviolet rays to complete the waveguide layer 5.
[0046]
(Example 6)
[Optical Waveguide 5]
Another embodiment of the present invention will be described with reference to FIGS. First, a substrate 10 (silicone resin) having a recess was prepared by the method of Example 1 (FIG. 1A). Next, the PMMA solution as the core material 1 was filled in the recesses with the dispenser 11 and heated to form PMMA as the core material 1 (FIGS. 1B to 1C). At that time, the core material had a shape slightly lower than the concave surface. Subsequently, an ultraviolet curable epoxy resin as a clad material 2 ′ was filled in the concave portion with the ink jet printer 11 to form a raised shape (FIG. 5). The clad 2 ′ was completely cured by irradiating the entire surface with 1 J / cm ² of ultraviolet rays.
[0047]
On the other hand, another substrate 20 (glass) was prepared, and the entire surface was spin-coated with an ultraviolet curable epoxy resin as the clad material 2 (FIG. 1 (d)). The clad 2 was semi-cured by irradiating the entire surface with ultraviolet rays of 100 mJ / cm ² .
[0048]
Here, in a state where they are overlapped with each other, 1 J / cm ² of ultraviolet light is irradiated from the side of another substrate to bond the clad 2 ′ and the clad 2 and completely cure the clad 2 (FIG. 1 (e)). .
[0049]
After peeling off the substrate 10 having the recess, metal mirror 4 was obtained by vapor-depositing metal Al on the mirror surface by mask vapor deposition. Further, an ultraviolet curable epoxy resin was applied to the entire surface as the clad 3 and irradiated with ultraviolet rays to complete the waveguide layer 5.
[0050]
(Comparative example)
[Optical Waveguide 6]
A comparative example will be described with reference to the first half of FIG. 1 and FIG. First, a substrate 10 (silicone resin) having a recess was prepared by the method of Example 1 (FIG. 1A). Next, the concave portion was filled with an ultraviolet curable epoxy resin as a core material 1 with a doctor blade (not shown) (FIGS. 1B to 1C). At that time, the core material had a shape slightly lower than the concave surface. The core 1 was completely cured by irradiating the entire surface with 1 J / cm ² of ultraviolet rays.
[0051]
On the other hand, another substrate 20 (glass) was prepared, and the entire surface was spin-coated with an ultraviolet curable epoxy resin as the clad material 2 (FIG. 1 (d)). The clad 2 was semi-cured by irradiating the entire surface with ultraviolet rays of 100 mJ / cm ² .
[0052]
In this state, by irradiating ultraviolet rays of 1 J / cm ² from the side of another substrate, the core 1 and the clad 2 were tried to adhere to each other and the clad 2 was completely cured (FIG. 1 (e)). .
[0053]
However, when the substrate 10 having the recesses was peeled off, the core 1 could not be transferred.
[0054]
【The invention's effect】
As can be understood from the above description, the present invention has the following effects.
[0055]
First, the process can be simplified by transferring the core material filled in the concave portion of the substrate onto the clad of another substrate. Secondly, by filling the core material only in the concave portion of the substrate, the use efficiency of the core material can be dramatically increased. Third, by making the filling shape a little higher than the concave surface, the adhesion can be improved and the transfer can be performed well.
[0056]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a method for producing an optical waveguide according to the present invention.
FIG. 2 is a cross-sectional view showing another example of a method for manufacturing an optical waveguide according to the present invention.
FIG. 3 is a cross-sectional view showing an example of a coated state of the core material of the present invention.
FIG. 4 is a cross-sectional view showing an example of a state of application of a conventional core material.
FIG. 5 is a cross-sectional view showing another example of the coated state of the core material and the clad material of the present invention.
FIG. 6 is a perspective view showing an example of an optical waveguide according to the present invention.
FIG. 7 is a perspective view showing another example of the optical waveguide of the present invention.
FIG. 8 is a cross-sectional view showing an example of a method for manufacturing a substrate having a recess according to the present invention.
FIG. 9 is a cross-sectional view showing another example of a method for manufacturing a substrate having a recess according to the present invention.
FIG. 10 is a cross-sectional view showing an example of a conventional method for manufacturing an optical waveguide.
FIG. 11 is a cross-sectional view showing another example of a conventional method for manufacturing an optical waveguide.
FIG. 12 is a cross-sectional view showing an example of a conventional mirror manufacturing method.
FIG. 13 is a cross-sectional view showing another example of a conventional method for manufacturing an optical waveguide and a mirror.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Core 1 '... Core 2 ... Cladding 2' ... Cladding 3 ... Cladding 3 '... Cladding 4 ... Metal mirror 4' ... Metal mirror 4 "... Metal mirror 5 ... Optical waveguide layer 6 ... Multilayer optical waveguide 7 ... Optical path 10 ... Substrate 10 'having recesses ... Substrate having recesses 11 ... Inkjet printer or dispenser 11' ... Inkjet printer or dispenser 20 ... Separate substrate 30 ... Substrate having projections 31 ... Substrate 32 ... Photoresist or epoxy resin 33 ... Laser beam 34 ... Silicone resin 40 ... Substrate 41 with recess ... Substrate 42 ... Photoresist or epoxy resin 43 ... Laser beam 50 ... Substrate 51 ... Silicon-containing resist or metal mask 52 ... Reactive ions 53 ... Ultraviolet exposure 54 ... Dicing blade 55 ... All Reflective mirror 56 ... Adhesion Agent

Claims (10)

  A method of manufacturing an optical waveguide composed of a core and a clad, in which only the concave portion of the substrate is slightly raised from the surface of the concave portion, and the core material is filled and cured to produce a core, and the clad material is applied to another substrate And a step of producing a substrate with clad by curing, a step of transferring the core to the substrate with clad, and a step of covering with a clad, wherein the core material and the clad material are resin, A method for manufacturing an optical waveguide, wherein at least one of the step of curing and the step of curing the clad material is semi-cured.   A method of manufacturing an optical waveguide comprising a core and a clad, in which only a concave portion of a substrate is filled with a core material and cured in a state of being lowered below the concave surface, and the remaining portion of the concave portion is slightly raised from the surface of the concave portion. Filling and curing one clad material to produce a core and a first clad; applying and curing a second clad material to another substrate; producing a second clad substrate; At least a step of transferring the core and the first clad to the second clad substrate, and a step of covering with the third clad, wherein the core material and the first to third clad materials are resin. A method for producing an optical waveguide, wherein at least one of the step of curing the first clad material and the step of curing the second clad material is semi-cured. 3. The method of manufacturing an optical waveguide according to claim 1, wherein the semi-cured core material or clad material is completely cured during the transfer step or after the transfer step.   The method for manufacturing an optical waveguide according to any one of claims 1 to 3, wherein an ink jet printer or a dispenser is used in the step of filling only the concave portion of the substrate with the core material or the clad material.   The method for manufacturing an optical waveguide according to claim 1, wherein at least one of the core material and the clad material is an ultraviolet curable epoxy resin.   The method for manufacturing an optical waveguide according to claim 1, wherein a concave portion of the substrate has a portion serving as a mold of an optical path conversion mirror.   The method for producing an optical waveguide according to claim 1, wherein at least a surface of the substrate having the concave portion is a silicone resin.   8. The method of manufacturing an optical waveguide according to claim 1, wherein the substrate having the concave portion is obtained by applying a liquid resin to the substrate having the convex portion, followed by curing and peeling.   9. The method of manufacturing an optical waveguide according to claim 8, wherein the substrate having the convex portion is a substrate in which a pattern of a photoresist or an ultraviolet curable epoxy resin is formed on the substrate.   A portion of the substrate having the convex portion, which becomes the mold of the optical path conversion mirror, or a portion of the substrate having the concave portion, which becomes the mold of the optical path conversion mirror, is processed by oblique irradiation of an excimer laser. The method for manufacturing an optical waveguide according to claim 8.

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