JP2000321459A - Optical waveguide and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an optical waveguide at a low cost without concern about safety. SOLUTION: A resin layer 2 formed on a substrate 1 is irradiated with light to form a 1st rugged part 4 and a metallic plating layer 6 is formed in such a way that the rugged part 4 is filled. A rigid body 7 is joined to the metallic plating layer 6 and the substrate 1 is separated to manufacture a die member 8 with a rugged part 9 formed by the transfer of the 1st rugged part 4 on the rear side of the metallic plating layer 6. The die member 8 is incorporated into a metallic mold and a resin molding consisting of a transparent resin having a low refractive index is formed. The resin molding has a 2nd rugged part 23 formed by the transfer of the rugged part 9. A transparent resin having a high refractive index is filled into each recess 26 of the rugged part 23 to form a core part 27 as an optical transmission part and a transparent resin coating 29 having a low refractive index is further formed on the rugged part 23 to obtain the objective optical waveguide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide and a method for manufacturing the same, and more particularly, to an optical waveguide that can be easily manufactured and a manufacturing method for efficiently manufacturing the same.

[0002]

2. Description of the Related Art FIG. 9 shows a manufacturing procedure of an optical waveguide generally used in the prior art. First,
As shown in (a), a transparent resin film 4 having a low refractive index is formed on a substrate 40.
1 is prepared, and then a resist layer 42 is formed on the resin film 41 of this material as shown in (b), and then the light 31 is passed through the mask material 30 as shown in (c).
Guess.

Next, the resist layer 42 is processed into a predetermined pattern as shown in FIG. 1D by developing it, and then put into a closed container 43 as shown in FIG. Thereafter, a corrosive gas 44 is supplied thereto as shown in (f), and the resin film 41 exposed from the resist layer 42 is etched to a predetermined depth as shown in (g).

[0004] (h) shows the resist layer 4 after the above processing.
2 shows an intermediate material of the optical waveguide obtained by removing No. 2. A concave-convex portion 45 having a predetermined shape is provided on the surface, and a concave portion 46 of the concave-convex portion 45 is filled with a high-refractive-index transparent resin in the next step (i). After the core portion 27 is formed, in the final step (j), a resin layer 29 made of a transparent resin having a low refractive index is formed on the core portion 27 to form a predetermined optical waveguide. Methods based on chemical methods are known as reliable and accurate manufacturing methods.

[0005]

However, according to the conventional method of manufacturing an optical waveguide, the formation of the concave and convex portions is performed by the resist layer 42.
The problem is that the manufacturing cost is high because it depends on the dry etching technology using photoresist, which requires many steps such as application, development, removal of unnecessary parts, etching, and removal of the remaining resist layer after etching. In addition, there were safety difficulties due to the handling of corrosive gases and vacuum containers, and they were not always satisfactory.

Accordingly, it is an object of the present invention to provide an optical waveguide which can be manufactured at low cost and without safety concerns, and a method for manufacturing the same.

[0007]

In order to achieve the above object, the present invention provides an optical waveguide having a low refractive index material surrounding a high refractive index core for optical transmission. A resin molded body molded from a transparent resin having a concave and convex portion on its surface, a core portion filled in a concave portion of the concave and convex portion and made of a transparent resin having a high refractive index, and the core It is an object of the present invention to provide an optical waveguide having a resin coating formed so as to cover a portion and made of a transparent resin having a low refractive index.

According to another aspect of the present invention, there is provided a method of manufacturing an optical waveguide, comprising: forming a coating of a low refractive index material around a high refractive index core for optical transmission.
A mold member having a concave and convex portion having a predetermined shape on its surface is incorporated into a mold, and the concave and convex portion is formed by injecting a transparent resin material having a low refractive index into the concave portion and a space connected to the concave portion in the mold. The core portion is formed by molding a resin molded body having an uneven portion on the surface by the transfer of the resin, and filling a high-refractive-index transparent resin into the concave portion of the uneven portion of the molded resin molded body. The present invention also provides a method for manufacturing an optical waveguide, wherein a transparent resin coating having a low refractive index is formed on the core portion.

Further, in order to achieve the above object, the present invention provides a method of manufacturing an optical waveguide in which a coating of a material having a low refractive index is formed around a core portion having a high refractive index for optical transmission. A first uneven portion having a predetermined pattern is formed by applying light to the resin layer formed on the surface and changing and removing the resin layer in a portion to which the light is applied or a portion to which the light is not applied. A first step, a second step of forming a metal plating layer so as to have a predetermined thickness on the substrate and the resin layer so as to fill the first uneven portion, By separating the resin layer, the convex and concave portions on the back surface of the metal plating layer formed by transferring the first concave and convex portions in the second step are exposed, and the concave portions of the convex and concave portions are formed. Remove the resin layer inside Third obtaining a mold member by Rukoto
Step, and incorporating the mold member into a mold in a state where a rigid body is placed behind the metal plating layer, and forming a transparent resin having a low refractive index on the convex and concave portions in the mold and a space portion connected thereto. A fourth step of molding a resin molded body having a second concave / convex portion on the surface by transferring the convex / concave portion by injecting a material, and a concave portion of the second concave / convex portion of the molded resin molded body A fifth step of forming the core by filling a high-refractive-index transparent resin into the core, and a sixth step of forming a low-refractive-index transparent resin coating on the core. It is another object of the present invention to provide a method for manufacturing an optical waveguide characterized by the above.

In the manufacturing method of the present invention, after the resin material is injected into the concave and convex portions of the mold member and the space portion connected thereto, pressure is applied to the resin material before the resin material is cooled or hardened and loses fluidity. In addition, it is preferable to solidify while maintaining that state.

If the resin material is poured and left standing until it is solidified, the resin material may not be able to completely fill the corners of the concave and convex portions of the mold member, and further, as the resin material cools, It is not preferable because a gap is formed between the mold and the mold member. These phenomena do not occur when pressure is applied while the injected resin material has fluidity.

[0012]

As the means for forming the first uneven portion in the invention of the present invention, a method of laser processing, light deterioration by light irradiation, photocrosslinking or the like is used. In the latter case, a photosensitive material whose molecules are destroyed by exposure to light or a photo-crosslinkable material whose molecules are reticulated by exposure to light is used as a constituent material of the resin layer.

The resin layer made of these materials is exposed to light through a mask material having a predetermined pattern of light transmitting holes, and the formed collapsed portion or non-crosslinked portion is removed with a solvent or the like. As a result, a first uneven portion having a predetermined shape is formed. Both of these methods and the method using laser processing enable high-precision fine processing, and are suitable processing methods for the present invention.

The rigid body placed behind the metal plating layer of the mold member when molding the resin molded body is for preventing the deformation of the mold member during the molding operation. Need not exist independently. For example, a part of a mold into which a mold member is incorporated may function as a rigid body.

When an independent rigid body is used, it is preferable to join the rigid body to the metal plating layer in advance rather than disposing it behind the metal plating layer when assembling the mold member into the mold. In this case, the bonding to the metal plating layer is performed after the second step or the third step.

Particularly preferred is after the second step, which can provide rigidity to the metal plating layer and the resin layer when the substrate and the resin layer are separated in the third step. Separation can be performed without causing deformation, peeling, or the like of these.

The separation of the resin layer from the substrate in the third step and the removal of the resin layer from the recesses of the convex and concave portions on the back surface of the exposed metal plating layer may be performed simultaneously or after the resin layer is separated once. The layer may be removed from within the recess.

Therefore, when the resin layer remains in the concave portion of the convex / concave portion, the convex / concave portion on the back surface of the metal plating layer which is exposed when the substrate and the resin layer are separated from each other. The expression referred to in the present invention includes such an expression state. In order to simultaneously separate the substrate and the resin layer and remove the resin layer from the recess, the substrate and the resin layer may be integrated with an adhesive.

In the second step, the formation of the metal plating layer on the substrate and the resin layer filling the first uneven portion is preferably performed after the conductive treatment on the substrate and the resin layer. Although it is conceivable to make the substrate and the resin layer itself conductive,
There are few such cases, and therefore, in many cases, the metal plating layer is formed after the substrate and the resin layer are subjected to a conductive treatment such as vacuum deposition or application of a conductive paint.

As a plating method, electroplating capable of thick plating is preferable, and the thickness of the formation can be arbitrarily determined depending on, for example, when the rigid body is joined to the metal plating layer. . It is preferable to polish the surface after forming a thick plating to obtain flatness.

At the time of molding the resin molded body in the fourth step, the base material is arranged at a position spaced from the convex and concave portions in the space, and molded in this state, so that the base material is formed at a predetermined location. It is possible to manufacture a composite resin molding having In this case, the base material is made of a metal or the like, and further, as the resin material in this case, application of an epoxy-based high-fluidity thermosetting resin having adhesiveness to the metal can be considered.

Examples of the resin having a low refractive index include polymethyl methacrylate, polydimethyl siloxane, epoxy resin, polymethyl pentene, and polyimide, which are excellent in transparency, and fluorides of main molecules of these resins having a molecular structure. Resins contained therein are used.

Among them, polydimethylsiloxane, epoxy resin or a resin containing a fluoride of the main molecule of these resins in the molecular constitution is particularly suitable as a constituent material of the resin molded product. When a resin molded body is formed from these resins, thermal deformation is unlikely to occur when the concave portion is subsequently filled with a resin having a high refractive index, and the operation is ensured. As the resin having a high refractive index, a resin having a processing temperature in consideration of the thermal deformability of the resin molded body is selected.

[0024]

Next, an embodiment of a method for manufacturing an optical waveguide according to the present invention will be described. FIG. 1 shows a manufacturing procedure. FIG. 1A shows a starting material in which an acrylate resin layer 2 is formed on one surface of a substrate 1. (B)
Is formed by irradiating a laser beam 3 using a YAG laser or the like and collapsing and extinguishing an irradiated portion to form a first uneven portion 4 having a predetermined pattern and shape as shown in (c). 3 shows a laser processing step.

FIG. 4D shows a conductive treatment step of making the entire surface of the uneven portion 4 conductive by vacuum-depositing a conductive thin film 5 of aluminum. (E) shows a plating step in which a metal plating layer 6 is formed on the thin film 5 by electroplating nickel. The metal plating layer 6 has a first uneven portion 4.
Is formed, and a predetermined thickness t is formed thereon.

A rigid body 7 made of a copper plate is joined to the metal plating layer 6 as shown in FIG. 1F, and then left after the substrate 1 is separated as shown in FIG. By removing the resin layer 2, a configuration as shown in FIG.

As a result of the separation of the substrate 1 and the removal of the resin layer 2, the projections and depressions 9 formed on the back surface of the metal plating layer 6 are exposed by the transfer from the first projections and depressions 4. As a result, a predetermined mold member 8 is formed.

FIG. 2 shows a molding step of the resin molded body. Mold 1 constituted by a combination of upper mold 11 and lower mold 12 having a pressing ram 10 at the center
The rigid body 7 is attached to the tip of the pressurizing ram 10, and the rigid body 7 and the mold member 8 are positioned in the recess 14 of the upper mold 11.

A predetermined space 15 is formed below the mold member 8 so as to be continuous with the concave and convex portions 9. An injection port 16 for injecting resin into the space 15 is formed in the center of the lower mold 12. Is provided. With the above configuration, a transparent fluorinated epoxy resin having a low refractive index and transparent as the resin material 17 is injected from the injection port 16.

FIG. 3 shows a procedure after the resin material 17 is injected. (A) shows the internal state of the mold 13 at the time when the injection of the resin material 17 is completed. Mold member 8
The resin material 17 is hard to turn in the corner portion 18 at the back of the convex / concave portion 9 or the corner portion 19 of the space portion 15, so that a gap is often formed in these portions.

Therefore, if the solidification proceeds in this state, the molded body becomes defective, but the treatment (b) prevents this. After the resin material 17 is injected, the resin material 17 is pressed by the pressing ram 10 while having fluidity at the time of injection. Corner portions 18 and 19 are completely filled.

Since this pressurization is continued until the resin material 17 is solidified, a precise resin molded body having no chipped portion can be obtained. As the pressurizing source, any type can be used as long as it can apply a predetermined pressure to the resin material 17 such as hydraulic pressure, hydraulic pressure, pneumatic pressure, spring force, or lever. Further, the pressing mechanism is not limited to a type depending on the pressing ram 10.

The inlet side of the injection port 16 in FIG. 3B is connected to the head 2 of the injection device for injecting the resin material 17.
Since 0 is connected, the pressing force A does not escape through the inlet 16, and the pressing force A acts uniformly on the entire area of the resin material 17.

FIG. 4 shows another failure mode which is likely to occur when the injected resin material is not pressurized. If the resin material 17 is injected at a high temperature, or if the mold is heated to a high temperature after the injection and then cooled as it is, the space between the molded body and the concave and convex portions 9 or between the molded body and the mold 13 is relatively small. A wide gap 21 occurs. This phenomenon in fine molding is fatal, and the treatment described in FIG. 3B is effective in preventing this phenomenon.

FIG. 5 shows the structure of the resin molded body 22 molded as described above. A second concave / convex portion 23 formed by transferring the concave / convex portion 9 of the mold member, and a portion 24 forming a filling port when filling a high refractive index resin in a later step.
Having.

FIG. 6 shows a process of forming an optical waveguide based on the resin molded body 22. First, a resin molded body 22 is prepared as shown in (a), and this is attached to another mold (not shown). Next, a transparent epoxy resin having a high refractive index is injected from the filling port 24 in the direction of the arrow 25 in FIG. 5, thereby filling the concave portions 26 of the concave and convex portions 23 in FIG. Thus, the core 27 is formed.

Next, after cutting from the position of the arrow 28 in FIG. 5 to remove the portion of the filling port 24, as shown in FIG. A resin coating 29 made of a material is formed, whereby a predetermined optical waveguide is manufactured.

FIGS. 7A and 7B show a method for forming the first uneven portion 4 in another embodiment.
(A) in the method (a) is a step of irradiating light 31 through a mask material 30 having a predetermined pattern;
Are the collapsed portions of the molecules generated in the resin layer 2 by this,
(C) shows that the resin layer 2 is formed by removing the collapsed portion 32.
The step of forming the first uneven portion 4 is shown in FIG.

(B) is an example in which a material having a property of being crosslinked by light is used as the resin layer 2. The difference from (a) is that a crosslinked portion 33 in which the molecules are reticulated by exposure to light 31. Are formed, and the cross-linked portion 33 is left and the other portion is removed in (c).
Both of the methods (a) and (b) are useful for forming the fine first uneven portion 4. In removing the collapsed portion 32 and the crosslinked portion 33, solvents compatible with these are used.

FIG. 8 shows another molding method of the resin molded body 22. A base material 3 having a through hole 34 in the center at a predetermined distance from the concave and convex portions 9 in the space 15.
5, whereby a resin molded body in which the base material 35 is integrated is molded. Base material 35
Is used as a component of a completed optical waveguide.

[0041]

As described above, according to the optical waveguide of the present invention, a resin molded body can be procured at a low cost in order to produce the resin molded body by molding. A significantly lower cost optical waveguide can be provided as compared with a conventional optical waveguide in which a molded body is manufactured.

Further, according to the present invention, a mold member having a concave and convex portion having a predetermined shape on its surface is prepared and assembled into a mold. By injecting a resin material, a resin molded body having an uneven portion by the transfer of the convex and concave portions is manufactured, and an optical waveguide is manufactured by using the resin molded body. It is possible to manufacture an optical waveguide in a simple manner, and to cope with the wear of the concave and convex portions only by replacing the mold member without replacing the entire mold.

In the case of the manufacturing method according to the present invention,
There is no safety concern that the conventional manufacturing method had,
Further, in the production of the mold member, the first minute concave and convex portion based on light is formed, the convex and concave portions are formed by transfer to the metal plating layer formed on this portion, and the mold member obtained thereby is used. The present invention also provides a technique for manufacturing an optical waveguide based on the molding of a resin molded body described above, so that an optical waveguide excellent in accuracy can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of an optical waveguide and a method for manufacturing the same according to the present invention, wherein (a) to (h) show a procedure for manufacturing a mold member.

FIG. 2 is an explanatory view showing a method for molding a resin molded body using the mold member manufactured according to FIG.

3A and 3B are explanatory views showing a molding procedure in the configuration of FIG. 2, wherein FIG. 3A shows an internal state of a mold before pressing a resin material, and FIG.

FIG. 4 is an explanatory view showing a defect phenomenon prevented by the procedure of FIG. 3;

FIG. 5 is a perspective view showing the structure of the resin molded body obtained according to FIGS.

6A and 6B are explanatory views showing a procedure for using a resin molded body as an optical waveguide, wherein FIG. 6A is a cross-sectional view of the resin molded body, FIG. 6B is a step of forming a core portion, and FIG. The forming process will be described.

FIGS. 7A and 7B show a method for forming a first uneven portion on a resin layer in the present invention, wherein FIG. 7A shows a case where a photodegradable material is used as the resin layer, and FIG. The following shows the case where a material having a property is used.

FIG. 8 is an explanatory view showing another embodiment for molding a resin molded body in the present invention.

FIG. 9 is an explanatory view showing a conventional method for manufacturing an optical waveguide.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Resin layer 3 Laser beam 4 First uneven part 5 Conductive thin film 6 Metal plating layer 7 Rigid body 8 Mold member 9 Convex and concave part 10 Pressing ram 11 Upper die 12 Lower die 13 Mold 15 Space 16 Injection 17 Resin material 22 Resin molded body 23 Second uneven portion 26 Depressed portion 27 Core portion 29 Resin coating 30 Mask material 31 Light 35 Base material

Claims (12)

[Claims] An optical waveguide in which a core portion having a high refractive index for light transmission is covered with a material having a low refractive index is molded from a transparent resin having a low refractive index. Resin molded body, filled in the concave portion of the uneven portion, formed to cover the core portion and the core portion formed of a transparent resin of a high refractive index, and formed of a transparent resin of a low refractive index An optical waveguide having a coated resin coating. 2. A method for manufacturing an optical waveguide, comprising forming a coating of a material having a low refractive index around a core portion having a high refractive index for optical transmission, comprising the steps of: A resin molded body having a concave and convex portion formed by transferring the concave and convex portion on the surface is formed by injecting a transparent resin material having a low refractive index into the concave and convex portion and a space connected to the concave portion in the mold. Forming the core portion by filling a high-refractive-index transparent resin in the concave portion of the uneven portion of the molded resin molded body; and forming a low-refractive-index transparent resin on the core portion. A method for manufacturing an optical waveguide, comprising forming a coating. 3. The pressure applied to the resin material injected into the convex and concave portions and the space portion connected to the convex and concave portions before losing fluidity,
3. The method of manufacturing an optical waveguide according to claim 2, wherein the pressure is continuously applied until the pressure is solidified. 4. A method of manufacturing an optical waveguide, wherein a coating of a material having a low refractive index is formed around a core portion having a high refractive index for light transmission, wherein light is applied to a resin layer formed on a surface of a substrate. The first portion having a predetermined shape is formed by altering and removing the resin layer in a portion to which light is applied or a portion to which no light is applied.
A second step of forming a metal plating layer so as to have a predetermined thickness on the substrate and the resin layer so as to fill the first uneven section. And separating the substrate and the resin layer to expose the concave and convex portions on the back surface of the metal plating layer formed by transferring the first concave and convex portions in the second step, A third step of obtaining a mold member by removing the resin layer in the concave portions of the convex and concave portions, and incorporating the mold member into a predetermined mold with a rigid body placed behind the metal plating layer. By injecting a transparent resin material having a low refractive index into the convex and concave portions and the space portion connected to the concave and convex portions in the mold, a resin molded body having a second concave and convex portion on the surface by the transfer of the convex and concave portions is provided. The fourth step of molding, and before molding A fifth step of forming the core portion by filling a high-refractive-index transparent resin into the concave portion of the second uneven portion of the resin molded body; A method for manufacturing an optical waveguide, comprising a sixth step of forming a transparent resin coating. 5. The method of manufacturing an optical waveguide according to claim 4, wherein the formation of the first uneven portion in the first step is performed by laser processing. 6. The resin layer in the first step forms a material forming a collapsed portion in which molecules are collapsed by being irradiated with light, or forms a crosslinked portion in which molecules are reticulated by being irradiated with light. The first uneven portion is formed by applying the light to the resin layer through a mask material of a predetermined pattern to form the collapsed portion or the crosslinked portion, and then formed. The method according to claim 4, wherein the method is performed by removing the resin layer in a portion other than the collapsed portion or the bridge portion. 7. The method for manufacturing an optical waveguide according to claim 4, wherein said rigid body is previously provided integrally with said metal plating layer after said second step or said third step. . 8. The method according to claim 8, wherein the forming of the metal plating layer in the second step is performed after conducting a conductive process such as vacuum deposition on the substrate and the resin layer in the first uneven portion. The method for manufacturing an optical waveguide according to claim 4, wherein 9. The method according to claim 4, wherein the resin material injected into the concave and convex portions and the space portion connected to the concave and convex portions in the fourth step is subjected to pressure before losing fluidity, and the pressure is continuously applied until the resin material is solidified. The method for manufacturing an optical waveguide according to claim 4, wherein: 10. The molding of the resin molded body in the fourth step is performed by arranging a base material in the space at a position spaced from the projections and depressions.
5. The semiconductor device according to claim 4, wherein the base material is integrated with the base material.
The manufacturing method of the optical waveguide described in the paragraph. 11. The resin material according to claim 4, wherein said resin material and said resin material are polydimethylsiloxane, epoxy resin, or a resin containing a fluoride of a main molecule of said resin in a molecular constitution. The manufacturing method of the optical waveguide described in the paragraph. 12. The optical waveguide according to claim 4, wherein said high-refractive-index resin is a resin having a processing temperature at which said resin molded body is not thermally deformed when forming said core portion. Manufacturing method.