KR100841797B1 - Method for manufacturing light waveguide and light waveguide manufactured therefrom - Google Patents

Abstract

The present invention comprises the steps of coating an ultraviolet photosensitive polymer on a substrate; Winding and fixing the film on a roller such that the coated polymer is facing up; Contacting the master with the coated polymer, wherein forming the core pattern while rotating the roller; Curing the patterned polymer by ultraviolet (UV) irradiation to form a lower clad; Injecting a core material into the pattern to form a core; And forming an upper cladding on the lower clad implanted with the core material.

By using the method of manufacturing the optical waveguide according to the present invention, it is possible to manufacture a continuous long length optical waveguide that is not limited to the size of the master.

Description

Method for manufacturing light waveguide and light waveguide manufactured therefrom

1 illustrates a method of manufacturing a continuous long optical waveguide according to the present invention.

Figure 2 is a diagram showing a cross section of the master of the present invention.

3 is a cross-sectional view of an optical waveguide according to the present invention.

<Description of the symbols for the main parts of the drawings>

1. Unwinder 2. Winder

3. UV Exposure Machine 4. 9. Clad Coater

5. UV blocking film 6. Master

7. Lip coater 8. Press roller / heater

11. Base material 12. Bottom cladding

13. Core 14. Upper Clad

The means of transmitting information using various types of electrical wiring, including printed circuit boards, led the 20th century electronic age and was applied to most industries such as computers, automobiles and mobile phones. However, with the recent increase in the use of the Internet, as the speed of information and the increase in capacity have increased, problems such as the limitation of speed occurring when using electrical wiring, the crosstalk characteristic between electric lines, the limitation of the mounting density, and the noise (EMS: Electro Magnetic Susceptibility) Has emerged and requires new means of communication. In order to overcome the recent limitations of electrical wiring according to these needs, it is intended to use an optical connection.

Therefore, in order to overcome the limitations of electrical wiring as described above, the development of technology for a printed circuit board having an optical waveguide inserted therein has been rapidly developed. In particular, long-wavelength optical waveguides are required for applications in next-generation high-speed parallel computers, information transfer between systems, and optical connections to the back plane.

As a method of manufacturing an optical waveguide, a silica process is generally used, which is formed by depositing silica and performing an etching process by flame hydrolysis deposition (FHD) or plasma enhanced chemical vapor deposition (PECVD). . Although the optical waveguide manufacturing method by the silica process can realize good characteristics, the production cost is expensive, and the manufacturing process is complicated and not suitable for commercial mass production, and the optical waveguide length is limited to the photo mask size. .

Therefore, research into the manufacture of optical waveguides using polymers has been actively conducted recently. Polymers are fast manufacturing, cost effective, have high yields and low light losses, making them suitable for optical waveguide materials. Typical methods for producing optical waveguides using polymers include wet etching, dry etching, and embossing. Although each has advantages and disadvantages, there are limitations in commercial mass production and the manufacture of long length optical waveguides beyond the size of photo masks. In this way, the manufacture of optical waveguides requires a mask for photolithography or a master for embossing, which can complicate the process or limit the length of the optical waveguide.

In order to manufacture a long optical waveguide, a photo mask or a master of that size is required. However, large photolithography is not easy, and the LiGA process, photoresist patterning, etching, and electroplating methods, which are typical methods for manufacturing masters, are long, about 4 inches (10 cm) beyond the wafer size. Difficulty in manufacturing masters)

In order to solve this problem, a roll patterning method is used, in which a pattern such as a concave groove or a cavity is engraved along the circumferential direction on the outer circumferential surface of one of the pair of pressure rollers, so that resin is applied to the surface. When the used sheet passes between the pressure rollers, the resin is formed in a pattern and cured. The roll patterning method has an advantage of manufacturing a long optical waveguide irrespective of the length of the master, but requires a difficult technique to inscribe a pattern on the roll, the width, depth error and There is a problem that the surface roughness must be properly maintained.

In order to improve the problems of the prior art as described above, the first technical problem to be achieved by the present invention is to provide a method of manufacturing an optical waveguide having a continuous long length without being limited to the size of the master.

A second technical object of the present invention is to provide an optical waveguide manufactured using the above method.

The present invention to solve the first technical problem,

Coating an ultraviolet photosensitive polymer on the substrate;

Winding and fixing the film on a roller such that the coated polymer is facing up;

Contacting the master with the coated polymer, wherein forming the core pattern while rotating the roller;

Curing the patterned polymer by ultraviolet (UV) irradiation to form a lower clad;

Injecting a core material into the pattern to form a core; And

It provides a method of manufacturing an optical waveguide comprising the step of forming an upper clad on the lower clad implanted with the core material.

According to one embodiment of the invention, it is preferable that the master is made of a transparent glass substrate.

According to another embodiment of the present invention, it is preferable that the pattern formation and curing occur simultaneously.

According to another embodiment of the present invention, the core forming step of the step of injecting the core material along the lip coater, the gap between the press roller as the sum of the film thickness and the bottom clad thickness of the core material to the lower clad pattern It is preferred to have a certain amount of filling to minimize the slab of the core, to fix the core material in the pattern through soft baking at 70 ℃ to 100 ℃, and ultraviolet curing step for 40 seconds to 5 minutes. .

According to another embodiment of the present invention, the lower cladding has a thickness of 65 μm to 82.5 μm and the upper cladding has a thickness of 15 μm to 20 μm.

According to another embodiment of the present invention, it is preferable that the pattern is 50 µm to 62.5 µm in length and width.

According to another embodiment of the present invention, the pitch between the center points of the core is preferably 100㎛ to 300㎛.

The present invention to solve the second technical problem,

An optical waveguide manufactured using the above method is provided.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the scope of the present invention should not be construed as being limited due to the embodiments described below.

Referring to Figure 1 describes a method for manufacturing a continuous long optical waveguide according to the present invention.

The substrate from the unwinder 1 proceeds with a roller and first coats the ultraviolet photosensitive polymer on the substrate by means of a clad coater 4, and then the coated polymer is directed upwards to the master 6. ) Is rolled up and fixed between the mounted rollers. In this case, the substrate may vary depending on characteristics required for the optical waveguide, that is, flexibility, heat resistance, pressure resistance, and the like, and a polyimide film and a polyethylene naphthalate film may be used. The ultraviolet photosensitive polymer may be an epoxy or acrylate-based polymer capable of photo-crosslinking in a molecular structure.

At this time, the master is brought into contact with the coated polymer, and the pattern of the master 6 is transferred to the polymer on the substrate. At the same time, the ultraviolet light is exposed to the ultraviolet light 3, and the ultraviolet light passes through the master 6 to allow the master 6 ) Is hardened in the state of being transferred to the coated polymer to form the lower clad. An enlarged cross section of the master is shown in FIG. 2. Since the master should have a light transmitting property, it is preferable that the master is made of a glass substrate, and may be manufactured through an etching process which is a general weave. In this case, UV exposure is preferably performed for 40 seconds to 5 minutes. If it is less than 40 seconds, non-crosslinking may adversely affect optical properties. If it is larger than 5 minutes, there is a problem of deformation of the base film due to heat of the exposure machine. Not desirable

The core is a material in which a dopant is added to the lower clad material to increase refractive index, and as the dopant, bromo benzene, benzyl butyl phthalate, benzyl benzoate, diphenyl phthalate, and the like may be used. Curing conditions of the core is the same as the lower cladding.

Thereafter, the core material is injected into the pattern using the lip coater 7, and the core is formed by pressing, heating, and ultraviolet curing with the press roller / heater 8 and the ultraviolet exposure machine 3. The compression minimizes slab in the core by making the gap between the press rollers the sum of the film thickness and the bottom clad thickness. If the gap between the press rollers is smaller than the sum of the thicknesses, there is a problem of crushing the pattern. If the gaps are larger than the sums of the thicknesses, the slab of the core becomes large, which is not preferable because of problems in optical properties.

After the core material is injected into the pattern, the soft material is subjected to soft baking at 70 ° C. to 100 ° C., preferably 75 ° C. to 97 ° C., more preferably 80 ° C. to 95 ° C. while passing through the press roller / heater 8. The core material is fixed in the pattern. If the soft baking temperature is less than 70 ℃ does not remove the solvent in the polymer has a bad effect on the core properties, and if it is larger than 100 ℃ because a portion of the polymer is hardening proceeds because the elaborate shape is difficult to form the pattern is not preferable.

Finally, using the clad coater 9 and the ultraviolet exposure machine 3 on the lower clad into which the core material is injected, the optical waveguide is manufactured by forming the upper clad in the same manner as the lower clad. Curing conditions of the upper clad are the same as the lower clad. The prepared optical waveguide can be wound and stored by the winder (2).

3 shows a cross section of an optical waveguide manufactured according to the present invention, which is stacked in the order of the substrate, the lower cladding, the core, and the upper cladding.

The thickness f of the base material varies depending on the characteristics required for the optical waveguide, that is, flexibility, heat resistance, pressure resistance, and the like, and is typically 10 μm to 100 μm, and the thickness e of the lower clad 12 is 65 μm to 82.5 μm. The thickness (d) of the upper clad is 15 μm to 20 μm, and the pattern of the core is a square having a width (c) and a length (b) of 50 μm to 62.5 μm.

The pitch (a) between the center points of the core can be freely designed according to the array spacing with the light emitting and receiving elements, and can be designed small as long as there is no light interference between the elements. The pitch is preferably from 100 μm to 300 μm, more preferably from 125 μm to 275 μm, and preferably 250 μm to match the array spacing of conventional light emitting device products.

The reason that the size of the core pattern is 50 μm to 62.5 μm is to be applied to a connection with a general multimode device or a multimode fiber (core size of 50 μm to 62.5 μm). The error range of the core pattern size is usually less than 5 μm. Do. The cladding thickness depends on the refractive index difference from the core, usually 1/3 to 1/4 of the core thickness. Since it is a multi-layer coating (3 layer coating of clad / core / clad), it is necessary to take into account the interlayer stress, the mechanical properties of the waveguide (flexibility, pattern collapse due to external pressure, etc.), and thus the optimum thickness of the clad is required depending on the material.

The number of core portions per optical waveguide depends on the application system. The greater the number of core parts, the greater the signal transmission capacity. This patent relates to the production of twelve core parts (12 channels) and the number of core parts can be adjusted according to the number of core patterns of the master.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be apparent from the appended claims.

By using the method of manufacturing the optical waveguide according to the present invention, it is possible to manufacture a continuous long length optical waveguide that is not limited to the size of the master.

Claims (8)

delete Coating an ultraviolet photosensitive polymer on the substrate; Winding and fixing the film on a roller such that the coated polymer is facing up; Contacting the coated polymer with a transparent glass substrate, wherein the roller is rotated to form a core pattern; Curing the patterned polymer by ultraviolet (UV) irradiation to form a lower clad; Injecting a core material into the pattern to form a core; And And forming an upper clad on the lower clad implanted with the core material. The method of manufacturing the optical waveguide according to claim 2, wherein the pattern formation and the curing occur simultaneously. 3. The method of claim 2, wherein said core forming step comprises the steps of: injecting a core material along the lip coater; Making the gap between the press rollers the sum of the film thickness and the bottom cladding thickness to fill the core material with a predetermined amount in the bottom clad pattern to minimize the slab of the core; Fixing the core material in the pattern through soft baking at 70 ° C. to 100 ° C .; And Method for producing an optical waveguide, characterized in that consisting of an ultraviolet curing step for 40 seconds to 5 minutes. The method of claim 2, wherein the lower cladding has a thickness of 65 to 82.5 μm and the upper cladding has a thickness of 15 μm to 20 μm. The method of manufacturing an optical waveguide according to claim 2, wherein the pattern has a width and length of 50 µm to 62.5 µm. The method of manufacturing the optical waveguide according to claim 2, wherein the pitch between the center points of the cores is 100 µm to 300 µm. An optical waveguide manufactured using the method of any one of claims 2 to 7.

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