JPH0486707A - Production of optical waveguide - Google Patents

Abstract

PURPOSE:To form the optical waveguide including a rib type optical waveguide on an opaque substrate by packing a liquid material into a stamper having the recessed shape of an optical waveguide shape and joining the opaque substrate onto the optical waveguide layer cured by irradiation with energy, then removing the stamper. CONSTITUTION:A UV curing resin 2A is dropped onto the stamper 1 having a hollow groove 1a corresponding to a rib part and is irradiated with UV rays after spin coating, by which the UV curing resin 2A is cured; thereafter, the opaque substrate 4 is joined onto the UV curing resin 2A by using a joining material 3, such as epoxy resin or thermosetting resin. A material having the refractive index smaller than the refractive index of the UV curing resin 2A is selected as the joining material 3 so as to allow light guiding in a core layer. After the opaque substrate 4 is joined into the UV curing resin 2A, the stamper 1 is peeled to form the core layer having the rib part 2a on the opaque substrate 4. The optical waveguide is formed on the opaque substrate by using the liquid material which is cured by the light energy in this way.

Description

BACKGROUND TECHNICAL FIELD OF THE INVENTION The present invention relates to optical waveguides including two-dimensional optical waveguides such as optical waveguide layers formed on a substrate, three-dimensional optical waveguides such as rib-type optical waveguides, etc. Regarding the manufacturing method.

Conventional technology and its problems Taking a J-shaped optical waveguide as an example, it is a core layer formed on a substrate, and a rib portion is formed integrally with the core layer along the propagation direction of light. .

In the plane perpendicular to the light propagation direction, the propagating light is confined by the refractive index difference between the core layer and air and the refractive index difference between the core layer and the substrate in the thickness direction of the core layer. (in the width direction of the rib part).

Confinement is achieved by utilizing the phenomenon that the effective refractive index near the rib portion increases due to the thickness of the rib portion being thicker than other portions of the core layer.

The present applicant fills a space between a stamper having a groove corresponding to a rib portion and a substrate with a liquid material that hardens when energy is applied thereto, and irradiates the liquid material with energy from the substrate side to form the liquid material. A method of manufacturing a rib-type optical waveguide was proposed by curing and then peeling off the stand bar (Japanese Patent Application No. 1-248107). However, according to this manufacturing method, the substrate must be transparent if it is a liquid material or one that is cured by light energy. It is only possible to fabricate a rib-type optical waveguide on an opaque substrate.

SUMMARY OF THE INVENTION OBJECTS OF THE INVENTION An object of the present invention is to provide a manufacturing method capable of manufacturing an optical waveguide including a rib-type optical waveguide on an opaque substrate.

Structure and Effects of the Invention The method for manufacturing an optical waveguide according to the present invention includes: (1) preparing a stamper having a concave shape in the shape of an optical waveguide to be manufactured; filling the stamper with a first liquid material that hardens by irradiating energy; and irradiating energy. The method is characterized in that an optical waveguide layer is formed by curing the first liquid material, an opaque substrate is bonded onto the cured optical waveguide layer, and then the stamper is removed.

The optical waveguide layer is a concept that includes a core layer having a core portion in a rib-type optical waveguide, and an optical waveguide layer as a representative example of a two-dimensional optical waveguide.

In addition, liquid materials that harden by energy irradiation include photocurable or thermosetting resins, such as ultraviolet (UV)
There is hardened resin. Further, as the inorganic material, a coating liquid for forming a thermosetting film can be mentioned. Liquid state also includes gel state.

According to the manufacturing method of the present invention, an optical waveguide can be formed on an opaque substrate using a liquid material that hardens upon irradiation with light energy.

Therefore, the materials used when forming an optical waveguide on an opaque substrate are not limited to thermosetting materials, etc.
The range of materials that can be used to form optical waveguide layers is expanding.

According to this invention, a buffer layer can also be formed between the optical waveguide layer and the opaque substrate.

In this case, a transparent substrate is prepared, and an optical waveguide layer is formed by curing the first liquid material, and then a second liquid material that is hardened by energy irradiation is formed between the optical waveguide layer and the transparent substrate. By injecting a liquid material and curing the second liquid material by irradiating energy, a buffer layer having a refractive index lower than that of the optical waveguide layer is formed, the transparent substrate is removed, and a layer is formed on the buffer layer. An opaque substrate is bonded to the opaque substrate, and then the process moves to the step of removing the stand bar.

By forming a buffer layer between the optical waveguide layer and the opaque substrate, an opaque substrate can have an arbitrary refractive index regardless of the refractive index of the opaque substrate or the refractive index of the material joining the opaque substrate and the optical waveguide layer. Alternatively, it becomes possible to use a bonding material, which facilitates the design of the optical waveguide.

After removing the transparent substrate, a third liquid material is further injected between the buffer layer and the second transparent substrate, and this is cured by energy irradiation to form a second buffer layer. By repeating the buffer layer forming step of removing the transparent substrate a required number of times and moving on to the bonding step of the opaque substrate after removing the last transparent substrate, it is possible to form an arbitrary number of stages of buffer layers.

The method for manufacturing a rib-type optical waveguide according to the present invention includes preparing a standber having a concave shape of the optical waveguide to be manufactured and a transparent substrate, and injecting a liquid material that hardens by energy irradiation between the standber and the transparent substrate. , forming an optical waveguide layer by curing the liquid material by irradiating energy, removing the transparent substrate, bonding an opaque substrate on the optical waveguide layer, and then removing the stand bar. shall be.

With this manufacturing method, an optical waveguide can be manufactured on an opaque substrate using a liquid material that hardens when irradiated with light energy.

When providing a buffer layer between the optical waveguide layer and the opaque substrate, the following procedure is performed.

That is, 1. A standber having a concave shape of an optical waveguide to be manufactured and first and second transparent substrates are prepared, and a first liquid material that is cured by energy irradiation is placed between the standber and the first transparent substrate. is injected and irradiated with energy to harden the first liquid material to form an optical waveguide layer, remove the first transparent substrate, and bond the optical waveguide layer and the second transparent substrate. A second liquid material that is cured by energy irradiation is injected between the layers, and a buffer layer having a refractive index smaller than that of the optical waveguide layer is formed by irradiating energy and curing the second liquid material. The transparent substrate No. 2 is removed, an opaque substrate is bonded onto the buffer layer, and then the stand bar is removed.

This makes it possible to manufacture an optical waveguide using an opaque substrate or bonding material with any refractive index.

Of course, it is also possible to form the buffer layer in multiple stages.

DESCRIPTION OF EMBODIMENTS FIG. 1 shows the manufacturing process of a rib-type optical waveguide according to a first embodiment of the present invention.

First, a stand bar 1 having a groove 1a corresponding to a rib portion is prepared.

This standby 1 is manufactured, for example, as follows.

An electron beam resist is applied onto the substrate, a rib pattern is drawn on the resist using an electron beam, and then developed, thereby producing a master having a residual film resist that will become the ribs on the substrate. Next, nickel (Ni) is deposited on the second master by electroforming, and by separating the master, a nickel standby is obtained.

UV (ultraviolet) curing resin 2A, which is the material for the core layer, is dropped onto the prepared stamper 1, and the top surface thereof is spin-coated to form a hedge. Then, UV rays are irradiated onto the U~' cured resin 2A from its upper surface to cure the UV cured resin 2A (FIG. 1(A)). After the UV curing resin 2A is cured, an opaque substrate 4 is bonded onto the UV curing resin 2A using a bonding material 3 such as an epoxy resin or a thermosetting resin (FIG. 1(B)). As the bonding material 3, a material having a refractive index smaller than that of the UV curing resin 2A is selected so that optical waveguide is possible in the core layer.

After bonding the opaque substrate 4 onto the UV curing resin 2A, the stamper 1 is peeled off (FIG. 1(C)).

As a result, the core layer 2 having the rib portion 2a is placed on the opaque substrate 4.
or formed.

As the material for the core layer R, for example, a thermosetting material can be used in addition to the UV curing resin. Examples of thermosetting inorganic materials include coating liquids for forming thermosetting films. There are many types of coating liquids, and Zr02Ti02. A material containing Ag2O3, SiO□, etc. is suitable. Furthermore, as the material of the core layer 2, M N
A (refractive index 1.8), PTS (polydiacetylene, refractive index 1.H), kDP (kH,, PO4)
It is possible to use nonlinear organic and inorganic optical materials such as

FIG. 2 shows the manufacturing process of an optical waveguide according to a second embodiment of the present invention.

A stamp I having grooves 13 corresponding to the rib portions is prepared. UV curing resin 2, which is the material of the core layer, is placed on the stamper 1.
A is dropped, a transparent substrate 5 is placed on top of the transparent substrate 5, and pressure is applied between the stamper 1 and the transparent substrate 5 so that the distance between the stamper 1 and the transparent substrate 5 or a predetermined value is maintained, and if necessary, vibration. UV rays are irradiated from the back side of the transparent substrate 5,
The UV curing resin 2A is cured (FIG. 2(A)).

The transparent substrate 5 is peeled off from the UV curing resin 2A (see Fig. 2).
B)). The adhesion between the transparent substrate 5 and the UV curing resin 2A?
The combination of the UV curing resin 2A, the stamper] and the transparent substrate 5 is considered so that the adhesion is weaker than the adhesion between the V curing resin 2A and the stamper l.

The opaque substrate 4 is bonded onto the UV curing resin 2A using a bonding material 3 such as epoxy resin or thermosetting resin (
Figure 2 (C)).

After being bonded onto the opaque substrate 4 or the UV curing resin 2A,
Peel off the star and bar 1 (Fig. 2(D)).

As a result, the core layer 2 having the rib portion 2a is placed on the opaque substrate 4.
or formed.

FIG. 3 shows the manufacturing process of an optical waveguide according to a third embodiment of the present invention.

The steps in FIGS. 3(A) and (B) are as shown in FIG. 2(A) above.
) and (B), so the explanation will be omitted.

After removing the transparent substrate 5, on top of the two cured UV cured resins... resin that hardens from a liquid state and becomes the material for the Nofa layer.
The transparent substrate 7 is placed on top of it, and pressure is applied between the UV curing resin 2A and the transparent substrate 7 so that the distance between the UV curing resin 2A and the transparent substrate 7 or a predetermined value is reached. and vibration if necessary. UV curing resin can also be used as the material for this buffer layer. The refractive index of UV-curable resins can be changed by changing the fluorine content. UV curing resin 6 which becomes a buffer layer
The refractive index of A is made smaller than the refractive index of the UV curable resin 2A which becomes the core layer. Ultraviolet rays are irradiated from the back side of the transparent substrate 7 to cure the UV curing material 6A (see Fig. 3 (C).
)).

After that, the transparent substrate 7 is peeled off from the UV curing resin 6A (
Figure 3 (D)). In this case as well, the adhesion between the UV curing resin 6A and the transparent substrate 7 is made weak.

The opaque substrate 4 is bonded onto the resin material 6A using a bonding material 3 such as epoxy resin or thermosetting resin (third
Figure (E)).

After the opaque substrate 4 is bonded onto the resin material 6A, the stamper 1 is peeled off (FIG. 3(F)). As a result, an optical waveguide is obtained in which the buffer layer 6 is formed on the opaque substrate 4, and the core layer 2 having the rib portions 2a is further formed thereon.

After forming the cured UV cured resin 2A on the stamper 1 through the manufacturing process shown in FIG. 1(A), the process shown in FIGS.
It is also possible to proceed to the manufacturing process shown in (F). Even in the case of method 2, a core layer having rib portions can be formed on an opaque substrate with a buffer layer interposed therebetween.

Furthermore, by repeating the steps shown in FIGS. 3(C) and 3(D), it is possible to form a plurality of buffer layers.

[Brief explanation of drawings]

1(8) to (C) show the manufacturing process of a rib-type optical waveguide according to the first embodiment of the present invention. 0 FIGS. 3A to 3F show the manufacturing process of a rib-type optical waveguide according to a third embodiment of the present invention. FIGS. ... Stamper 2, core layer 2a... - rib portion 2A, U~' cured resin 3... - bonding material 7 4, opaque substrate 57, transparent substrate 6... buffer layer. 6A, resin material (No. (2) liquid material). (1st liquid material)

Claims (6)

[Claims] (1) Prepare a stamper having a concave shape in the shape of an optical waveguide to be manufactured, fill the stamper with a first liquid material that hardens by irradiating energy, and harden the first liquid material by irradiating energy. A method for manufacturing an optical waveguide, comprising: forming an optical waveguide layer by: bonding an opaque substrate onto the cured optical waveguide layer; and then removing the stamper. (2) After preparing a transparent substrate and forming an optical waveguide layer by curing the first liquid material, a second liquid material that is hardened by energy irradiation is provided between the optical waveguide layer and the transparent substrate. A buffer layer having a refractive index smaller than that of the optical waveguide layer is formed by injecting the second liquid material and curing the second liquid material by irradiating energy, removing the transparent substrate, and forming an opaque layer on the buffer layer. Claim 1: The step of bonding the substrates and then removing the stamper is performed.
) The method for manufacturing an optical waveguide according to (3) After removing the transparent substrate, a third liquid material is further injected between the buffer layer and the second transparent substrate and is cured by energy irradiation to form a second buffer layer. The method for manufacturing an optical waveguide according to claim 2, further comprising repeating the buffer layer forming step of removing the second transparent substrate a required number of times, and moving on to the opaque substrate bonding step after removing the last transparent substrate. (4) Prepare a stamper with a concave shape of the optical waveguide to be produced and a transparent substrate, inject a liquid material that hardens by energy irradiation between the stamper and the transparent substrate, and irradiate the energy to form the liquid material. A method for manufacturing an optical waveguide, comprising forming an optical waveguide layer by curing a material, removing the transparent substrate, bonding an opaque substrate on the optical waveguide layer, and then removing the stamper. (5) A stamper having a concave shape in the shape of an optical waveguide to be produced and first and second transparent substrates are prepared, and a first liquid that is hardened by energy irradiation is provided between the stamper and the first transparent substrate. forming an optical waveguide layer by injecting a material and curing the first liquid material by irradiating energy; removing the first transparent substrate; and forming the optical waveguide layer and the second transparent substrate. A second liquid material that is cured by energy irradiation is injected during the step, and a buffer layer having a refractive index smaller than that of the optical waveguide layer is formed by irradiating energy and curing the second liquid material. A method for manufacturing an optical waveguide, comprising: removing a second transparent substrate; bonding an opaque substrate onto the buffer layer; and then removing the stamper. (6) After removing the second transparent substrate, a third liquid material is further injected between the buffer layer and the third transparent substrate and cured by energy irradiation to form a second buffer layer. The method for manufacturing an optical waveguide according to claim (5), wherein the buffer layer forming step of forming a buffer layer and removing the third transparent substrate is repeated a required number of times, and after removing the last transparent substrate, the process moves to the step of bonding the opaque substrate. .