KR20040037614A - Method of manufacturing 2-dimensional polymeric optical waveguide using hot embossing process - Google Patents

Abstract

PURPOSE: A method for manufacturing two dimensional polymer optical waveguide by using a hot embossing process is provided to manufacture the two dimensional polymer optical waveguide having a high density and a cost effective in comparison with one dimensional optical waveguide. CONSTITUTION: A method for manufacturing two dimensional polymer optical waveguide by using a hot embossing process includes the steps of: (a) forming core pattern on both sides of the intermediate clad layer by pressing the top and bottom master into the intermediate layer under a predetermined temperature; (b) injecting the core material into the core pattern of the intermediate clad layer; and (c) attaching the top and bottom clad layer to the intermediate clad layer inserted thereinto the core material.

Description

Method for manufacturing 2-dimensional polymeric optical waveguide using hot embossing process

The present invention relates to a method for manufacturing a two-dimensional polymer optical waveguide, and more particularly, to a method for manufacturing a two-dimensional polymer optical waveguide using a two mold masters in a polymer optical waveguide structure using a hot embossing process. .

Optical media and optical waveguides are used as optical media in optical communication systems. Optical waveguides are manufactured in the form of planar optical waveguides. It is composed of layers, and light is transmitted through the core without leaking out of the cladding layer due to the difference between the refractive index of the core and the refractive index of the clad. Most of the planar optical waveguides are made of silica, and recently, researches for producing planar optical waveguides based on polymers have been actively conducted.

Optical waveguide manufacturing methods include a photolithography process, a photopolymer process, a laser direct writing process, and a hot embossing process.

The photolithography process uses a fine pattern forming technique used in semiconductor memory device fabrication processes to form a lower clad layer by coating and curing a polymer on a flat substrate, and curing the polymer by redrawing the polymer on the lower clad layer. Make the middle layer. Next, the SiN mask is again placed thereon, a photoresist is applied and baked. The photolithography process removes portions other than the core pattern of the photoresist layer and the SiN mask layer, and removes portions other than the mask pattern on which the core is formed by reactive ion etching. Next, the remaining SiN mask layer is removed, and the upper clad layer is applied and cured to complete the optical waveguide. Suitable polymers for this process include Acrylate, Benzo cyclobutene, Polysiloxane, and Polyimide.

In the photopolymer process, a lower clad layer is formed by applying and curing a polymer on a planar substrate. The polymer is cured by redrawing the polymer on the lower clad layer to form an intermediate layer. Then, a metal mask prepared in advance is placed on the polymer and irradiated with ultraviolet rays to form a core by removing a portion other than the portion irradiated according to the metal mask pattern using a polymer developer. Next, the polymer is applied again on the core layer to form an upper clad layer and then cured to complete the optical waveguide. Suitable polymers for this process include ultraviolet curing polymers.

The laser direct drawing process applies and cures a polymer on a planar substrate to form one clad layer. The waveguide pattern is directly formed by irradiating with a laser, or the waveguide pattern is formed by using a mask. At this time, the portion irradiated with the laser becomes higher in refractive index and has a higher refractive index than the clad to form a core layer, and the portion not irradiated with the laser is used as the clad. The upper clad layer is then applied and cured to complete the optical waveguide. Polymers suitable for this process include the polyimide series, and polymers having a synergistic effect of the refractive index due to the change of the refractive index by laser irradiation are used.

On the other hand, in the hot embossing process, the lower clad layer is formed by molding the structure of the core part using a mold master, the core material is injected into the structure where the core is formed, and then the upper clad layer is covered and attached to complete the optical waveguide.

Hereinafter, an example of a method of manufacturing a polymer optical waveguide by a hot embossing process will be described in detail with reference to FIGS. 1A to 1F.

1A and 1B, in the method of manufacturing a polymer optical waveguide using hot embossing according to the related art, first, a lower clad layer 12 is formed using a master 10 to form a core structure.

After deembossing (FIG. 1C), the material to be used as the core layer 14 is injected into the core-shaped structure and filled (FIG. 1D). Thereafter, the upper cladding layer 16 is covered and UV rays are irradiated for about 2 to 5 minutes to cure the core material (FIG. 1E). The upper cladding layer is attached to the lower cladding layer to complete the optical waveguide in which the core is formed. (FIG. 1F).

However, the above-described hot embossing method of the prior art only discloses a manufacturing method relating to the one-dimensional optical waveguide, but until now, no method for economically manufacturing the two-dimensional polymer optical waveguide has been disclosed.

Accordingly, an object of the present invention is to provide a new method for economically manufacturing a two-dimensional polymer optical waveguide that can be more dense and highly integrated than a one-dimensional optical waveguide using a hot embossing process.

Another object of the present invention is to produce a two-dimensional polymer optical waveguide in a very simple method in a short time, mass production is possible, and highly precise single-mode and multi-mode optical waveguide device regardless of the size of the optical waveguide It can be manufactured to provide a method that can be applied to various types of polymer optical waveguide device.

1A to 1F are flowcharts of a process for manufacturing a polymer optical waveguide according to the prior art.

2A and 2B are cross-sectional views of a two-dimensional polymer optical waveguide manufactured by a preferred embodiment of the present invention.

3A to 3F are flowcharts illustrating a manufacturing process of a two-dimensional polymer optical waveguide according to a preferred embodiment of the present invention.

In order to achieve the above technical problem, the present invention provides a method for manufacturing a two-dimensional polymer optical waveguide, (a) by pressing the upper and lower masters having a pattern for forming a core to the intermediate cladding layer at a predetermined temperature to the intermediate cladding layer Forming a core pattern on both sides of (b) injecting the core material into the core pattern of the intermediate clad layer, and (c) attaching the upper and lower clad layers to the intermediate clad layer into which the core material is injected; It provides a method for manufacturing a two-dimensional polymer optical waveguide comprising a.

Preferably, the attaching step may include pressing the upper and lower cladding layers at a constant pressure while irradiating UV light for about 2 to 5 minutes, and the lower cladding layer may further include a silicon substrate alone or below. Can be.

The core layer formed by the two-dimensional lamination can be manufactured with a waveguide in which the X-displacement positions are at the same center points of the upper and lower cores, and the pitch between the center points of the cores is preferably 100 µm to 300 µm.

In addition, the core layer formed by the two-dimensional lamination may be manufactured so that the position of the stacked core layer is located at the X-displacement such that the point at which half of the pitch between the upper both cores is half the point at the lower core. .

On the other hand, the core pattern may be 5 to 200㎛ horizontally and vertically, respectively, the thickness of the intermediate cladding layer may be 132㎛ ~ 450㎛.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; However, embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

2A and 2B are cross-sectional views of a two-dimensional polymer optical waveguide manufactured by a double-sided hot embossing process according to a preferred embodiment of the present invention. These represent two types of two-dimensional polymer optical waveguides depending on the position of the core layer. FIG. 2A is a waveguide in which the X-displacement position of the core layer formed by the lamination is at the same position as the center point of the upper and lower cores, and FIG. 2B shows that the position of the core layer formed by the lamination is 1 An example is made of a waveguide positioned at an X-displacement such that a point at which / 2 is a point at which 1/2 is a lower core.

Hereinafter, the manufacturing process of the above-described two-dimensional polymer optical waveguide will be described in detail with reference to FIGS. 3A to 3F.

3A to 3F are process diagrams illustrating a process of forming a fine pattern structure formed at an intaglio of a two-dimensional polymer optical waveguide by a double-sided hot embossing process. The double sided hot embossing process refers to a process of hot embossing on both sides using two masters simultaneously.

In the step of FIG. 3A, a polymer sheet to be hot-embossed is disposed in the middle of the mold master positioned at the top and the bottom. The polymer sheet is a portion to be formed of the intermediate cladding layer 120. The upper master 110 and the lower master 130 are each added with a heating and cooling device 140.

Referring to FIG. 3B, the upper and lower masters 110 and 120 are disposed on both surfaces at a temperature of about 10 to 100 ° C. higher than the glass transition temperature Tg depending on the type of polymer sheet to be used as the intermediate clad layer 120. The polymer sheet is pressed under a constant pressure. Glass transition temperatures have different values for different materials. Preferred polymer sheets are thermoplastic polymers (PMMA, PC, COC, PS) or PMMA, PC, COC, PS, etc., to which Lactone and the like are added to improve the loss and passion properties. Then, the predetermined pressure is maintained for a predetermined time, for example, about 1 to 10 minutes, and the temperature is cooled to 80 to 100 ° C. Therefore, core patterns aligned by the master are formed on the upper and lower portions of the intermediate clad layer 120, and the grooves are injected with the core material to be used as the core layer. The upper and lower masters 110 and 120 have embossed patterns for core formation.

Referring to FIG. 3C, when the temperature reaches 80 to 100 ° C. below the glass transition temperature, the applied master is released from the polymer sheet to separate the upper and lower masters 110 and 130 and the intermediate clad layer 120. In this manner, an embossed sheet, i.e., an intermediate clad layer 120, containing the fine pattern structure of the core is manufactured.

FIG. 3D is a process diagram illustrating an example of attaching a lower clad layer 210 to an intermediate clad layer 120 having a micro pattern core structure of a micron unit manufactured by a double-sided hot embossing process. In the manufacturing method of FIG. 3D, the lower clad layer 210 is preferably applied when the thickness is about several tens of micrometers or less. That is, the lower clad layer 210 is formed on the silicon substrate 200 by spin coating, and the lower clad layer 210 is used as the lower clad layer 210. In this case, when the thickness of the lower clad layer 210 is not easy to be used alone, it is used by attaching it to a substrate. 3F illustrates a case where the lower cladding layer has a thickness of several tens of micrometers or more, and a polymer sheet is used as the lower cladding layer without forming a lower cladding layer on the silicon wafer by spin coating. This will be described later.

On the other hand, each dimension (a, b, c and d) of the intermediate cladding layer 120 having the fine pattern core structure formed by FIG. 3D will be described by way of example. The size of the core can be suitably utilized according to the application device such as single mode and multi-mode optical devices. For example, the width (a) and the length (b) are 5 to 200 μm, respectively. Intermediate pitch at the center of the core (c) is preferably in the range of about 100 to 300 ㎛, more preferably about 127 ㎛ or 250 ㎛, the intermediate clad layer comprising a core The thickness d of 120 may be manufactured in consideration of the dimensions of the core and the pitch between the cores, for example, about 132 μm to 450 μm.

Referring to FIG. 3E, first, a liquid core material is injected into a microchannel to form a core, covered with upper and lower clad layers 250 and 210, and irradiated with UV light for about 2 to 5 minutes, and an upper and lower clad layers ( The intermediate cladding layer 120 and the upper and lower cladding layers 250 and 210 are completely adhered to each other by pressing 250 and 210 at a constant pressure to form upper and lower cores. At this time, the material used as the core layer uses a UV-curing material having an adhesive force so that the upper and lower clad layers 250 and 210 are attached at the same time as curing. In addition, materials with TFPMA, BzMA, PFPMA, Lactone, etc., are added to the UV-curable material to improve the loss and passion properties. The refractive indices of the upper and lower cladding layers 250.210 and the core are applied differently according to single mode and multimode optical waveguide devices, and vary from about 0.3% to 2.0%.

Meanwhile, referring to FIGS. 3F and 3G, when the thickness of the lower clad layer 220 is several tens of micrometers or more, as described above, the lower clad layer is not directly formed on the silicon wafer by spin coating, and the polymer sheet is directly formed on the lower clad layer ( 220). Hereinafter, the process of forming the core and attaching the upper and lower clad layers is the same as the above process.

Meanwhile, in the present embodiment, as described with reference to FIG. 2A, only the case where the X-displacement position of the core layer formed as a stack is manufactured with a waveguide in which the center points of the upper and lower cores are located at the same position is described as an example. If necessary, it may be used in the fabrication of waveguides having variously modified two-layer core arrays.

On the other hand, the number of channels of the optical waveguide having a core formed of two layers is not particularly limited, and can be 1 to n, and the shape of the waveguide includes a straight line and a xn to nxn optical splitter. Optical couplers, nxn optical switches or optical modulators, nxn variable optical attenuators, and the like are possible. n is not specifically limited, The high effective range is 1-128.

Through this method, it is easy to form a micro-pattern structure in the polymer sheet (plastic), it is possible to directly use the optical lens, optical communication device, microfluidic device, etc., and the manufacturing process is simple It is suitable for low cost and mass production.

The optical waveguide manufactured through the above-described configuration can be economically manufactured with a two-dimensional polymer optical waveguide capable of higher density and higher integration than the one-dimensional optical waveguide by using a hot embossing process.

In addition, the single- and multi-mode optical waveguide device can be manufactured very precisely regardless of the size of the optical waveguide, and thus it is effective to be applied to various types of polymer optical waveguide devices.

Claims (10)

In the method of manufacturing a two-dimensional polymer optical waveguide, (a) pressing the upper and lower masters having the core forming pattern to the intermediate cladding layer at a predetermined temperature to form core patterns on both sides of the intermediate cladding; (b) injecting a core material into the core pattern of the intermediate clad layer; And (c) attaching the upper and lower clad layers to the intermediate clad layer into which the core material is injected. The method of claim 1, wherein the attaching step (c) comprises pressing the upper and lower clad layers at a constant pressure while irradiating UV light for about 2 to 5 minutes. How to make a waveguide. The method of claim 1, further comprising a silicon wafer under the lower cladding layer when the thickness of the lower cladding layer is several tens of micrometers or less. 2. The method of claim 1, wherein the core layer formed of the two-dimensional stack is made of a waveguide in which X-displacement positions are at the same center points of the upper and lower cores. The method of claim 1, wherein the pitch between the center points of the cores is 100 μm to 300 μm. 2. The core layer of claim 1, wherein the core layer formed of the two-dimensional stack is located at an X-displacement such that a position where the position of the stacked core layer is one half of the pitch between both upper cores is one half of the lower core. Method for producing a two-dimensional polymer optical waveguide, characterized in that it is manufactured to. The method of claim 1, wherein the core pattern has a width and a length of 5 μm to 200 μm, respectively. The method of claim 1, wherein the intermediate cladding layer has a thickness of 132 µm to 450 µm. The method of claim 1, wherein in the step (a), pressurization is performed at a temperature about 10 to 100 ° C. higher than the glass transition temperature (Tg). The method according to any one of claims 1 to 9, wherein the polymer sheet is a thermoplastic polymer (PMMA, PC, COC, PS) or PMMA, PC, COC or PS characterized in that the additive containing Lactone is contained in Method of manufacturing a two-dimensional polymer optical waveguide.