JP2001033629A - Manufacture of glass original disk, manufacture of stamper, and glass original disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the aligning of a photomask and hardly cause the peeling of an electrocast body in the middle of electrocasting process by providing a rough surface part and a mirror surface part on one side of a glass original disk for manufacturing a stamper. SOLUTION: A photoresist layer 5 is formed on the surface of a glass original disk 1 on which a rough surface part 2 and a mirror surface part 3 are formed. A photomask 6 having a plurality of deflection patterns 7 drawn thereon is closely adhered to the surface of the resist layer 5. It is exposed to UV light 9 to photosensitize the area corresponding to the pattern 7 and the area not in contact with the mask 6. The resist layer 5 is developed to leave a non- exposed part 10 on the mirror surface part 3 of the original disk 1. A conductive film is formed on the resist layer 5, and nickel electrocasting is performed to form an electrocast body 11 on the conductive film. The pattern of the non- exposed part 10 corresponding to the pattern 7 of the mask 6 is transferred to the electrocast body 11. The electrocast body 11 peeled from the original disk 1 is worked so that the rough surface part 2 is not left, whereby a stamper 12 can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a stamper used for manufacturing a light guide plate for a backlight device used for a liquid crystal display device, a glass master used for manufacturing the stamper, and a glass master used for manufacturing the stamper. It relates to a manufacturing method.

[0002]

2. Description of the Related Art A light diffuser provided with a so-called edge light type light guide plate in which light enters from a side end surface of a transparent plate and light is emitted from one surface (light exit surface) to perform illumination. The device is used as a backlight device used for a liquid crystal display device provided in a word processor, a personal computer, a thin television, or the like. In such a light diffusion device, a tubular light source is arranged on one side end surface of the light guide or on a side end surface facing each other, and the remaining light guide plate excluding the light incident side end surface and the light exit surface that emits light. The surface is provided with an element (hereinafter, referred to as a “deflection element”) that changes an angle of light transmitted through the light guide or an angle of light reflected by the light guide.

The light incident from the side end surface of the light guide changes its direction on the light exit surface and the surface opposite thereto and exits from the light exit surface, but the light guide bottom surface facing the light exit surface The light is totally reflected by the light guide and propagates in the light guide. Generally, the density distribution of the deflecting element and the angle at which the light is deflected by the deflecting element are determined so that the brightness of the light diffusion device becomes uniform over the entire light exit surface.

The above-mentioned deflecting element has a light guide surface coated with white ink or paint which scatters or reflects light, and a light guide surface provided with a concave / convex portion for scattering or reflecting light. And a light guide containing a light diffusing agent.

The above type of light guide is manufactured by screen printing or the like. However, if the composition of the white ink or paint changes, the light reflectivity changes and the brightness does not become uniform.
If dust in the air mixes with white ink or paint or adheres to a printing surface or a coating surface during a printing operation, unexpected scattering of light occurs due to the dust, and the intended brightness cannot be made uniform. Further, in the light guide of the above type, it is difficult to disperse the light diffusing agent in the base material with high reproducibility even if the deflection element is provided so as to have a predetermined density distribution.

[0006] For the above reasons, a light guide provided with a concave and convex portion such that light is scattered or reflected on the surface is used in many back illuminators of liquid crystal display devices.

FIG. 4 is a schematic view showing a conventional manufacturing process of a light guide having an uneven portion as a deflection element on the surface. FIG. 5 is a schematic diagram showing the configuration of the glass master after the development step of FIG. 4 as viewed from above. FIG. 4A shows a photoresist coating step. A disk-shaped glass master 21 whose surface is polished is placed on a turntable of a spin coater (not shown), and a positive photoresist is applied to the glass master 2.
1 is applied on the polished surface to form a photoresist layer 22.

FIG. 4B shows an exposure step. A photomask 23 which is rectangular and on which a plurality of patterns (hereinafter referred to as “deflection patterns”) corresponding to the deflection elements are depicted.
Is adhered to the surface of the photoresist layer 22. In the photomask 23, the deflection pattern portion transmits light,
Regions other than the deflection pattern portion do not transmit light. Light having a wavelength that the photoresist layer 22 is exposed to is exposed from the upper surface of the photomask 23. At this time, the photoresist layer 22
The region corresponding to the deflection pattern of the photomask 23 and the region not in contact with the photomask 23 are exposed to light, and an exposed portion 24 is formed.

FIG. 4C shows a developing step. The glass master 21 on which the exposed photoresist layer 22 is formed is attached to a developing device, the photoresist layer 22 is developed with a developing solution, and the developing solution is washed with pure water. At this time,
The region of the photoresist layer 22 corresponding to the deflection pattern of the photomask 23 exposed in the step of FIG. 4B is removed, and the photoresist layer 22 of the unexposed portion 25 remains on the glass master 21. In addition, the photoresist layer 2 in a region that is not in contact with the photomask 23 on the outer peripheral portion of the glass master 21.
2 is also removed.

In the glass master 21 after the development process, only the unexposed portion 25 remains, and the photoresist layer 22 in the region 30 corresponding to the deflection pattern of the photomask 23 and the region not in close contact with the photomask 22 is removed. Become. Therefore, as shown in FIG. 5, the surface 29 of the glass master 21 is exposed outside the unexposed portion 25.

FIG. 4D shows an electroforming step. By a sputtering method, chromium (C) is formed on the surface of the glass master 21 after the development process on which the photoresist layer 22 is formed.
r), a conductive film such as nickel (Ni) is formed, the glass master 21 on which the conductive film is formed is set in an electroforming apparatus, nickel is electroformed, and an electroformed body 26 having a deflection pattern transferred is formed. I do.

FIG. 4E shows a molding step. After the electroforming step, the electroformed body 26 is separated from the glass master, the outer periphery of the electroformed body 26 is processed into a desired shape, and the back surface is polished to obtain a stamper 27. The stamper 27 is mounted in a mold of an injection molding machine. A stamper 2 for molten resin such as acrylic resin
The light guide 28 can be obtained by injecting into a mold to which the 7 is attached and cooling.

[0013]

There are the following problems in the process of manufacturing a light guide having a concave and convex portion as a conventional deflection element.
Since the photoresist layer 22 is formed by a spin coating method, a disk-shaped glass master 21 is generally used. When manufacturing a large-sized light guide plate along with an increase in the area of the liquid crystal display device, it is necessary to increase the area of the glass master 21 as well.

In general, it is difficult to form a photoresist layer 22 with a uniform thickness on a large area glass master 21, and in particular, the film thickness distribution in the outer peripheral portion of the glass master 21 becomes non-uniform. In this case, the photomask 23 needs to be in close contact with the photoresist layer 22 in the middle to inner peripheral portions having a uniform film thickness distribution. The photomask 23 is brought into close contact with the outer peripheral portion of the photoresist layer 22 having a non-uniform thickness distribution, resulting in a problem that the shape of the deflection pattern becomes non-uniform and the surface of the light guide becomes rough. Was. If the photomask 23 is stuck to the wrong position of the photoresist layer 22 and the photomask 23 is peeled off from the photoresist layer 22 in order to change the contact position of the photomask 23, the surface of the photoresist layer 22 is removed. In this case, a defect may occur. In this case, the glass master 21 must be washed again to form the photoresist layer 22.

As shown in FIG. 5, the surface of the glass master 21 (the surface of the glass master 21 is mirror-polished) is exposed at the outer peripheral portion of the glass master 21 after the development step. I do. Glass master 21 shown in FIG.
By the electroforming step shown in FIG. 4D, an electroformed body 26 is formed on almost the entire surface on which the photoresist layer 21 is formed. However, on the outer periphery of the glass master 21, the conductor film and the electroformed body 26 are directly formed on the surface of the mirror-polished glass master 21, and the electroformed body 26 is formed during the electroforming process. In some cases, the glass master 21 was peeled off from the outer periphery.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is easy to align a photomask, and it is difficult for an electroformed body to peel off during an electroforming process. An object of the present invention is to provide a method for manufacturing a master and a method for manufacturing a stamper.

[0017]

According to a first aspect of the present invention, there is provided a method of manufacturing a glass master, wherein a mask having substantially the same outer shape as that of a photomask is brought into close contact with the surface of the glass master. And a step of roughening a region of the surface of the glass master except for a region where the mask is in close contact.

According to a second aspect of the present invention, there is provided a method of manufacturing a stamper, the method comprising: bringing a mask having substantially the same outer shape as that of a photomask into close contact with the surface of a glass master; A step of roughening an area other than an area where the mask is in close contact, a step of forming a photoresist layer on the surface of the glass master from which the mask has been peeled off, and the step of forming the photomask on the glass master with the roughened surface. Exposing the photoresist to the photoresist layer in accordance with the unexposed area, exposing the photomask from the photoresist layer, and developing the photoresist, and a conductive film on the developed photoresist layer. Forming an electroformed object by depositing an electroformed object on the conductor to form an electroformed object; and removing the electroformed object from the photoresist layer. The characterized in that it comprises a step of processing the desired configuration.

According to a third aspect of the present invention, there is provided a method of manufacturing a stamper, wherein a step of bringing a mask having substantially the same outer shape as the outer shape of the stamper into close contact with the surface of the glass master disk; A step of roughening an area excluding an area where the mask is in close contact, a step of forming a photoresist layer on the surface of the glass master from which the mask has been peeled off, and a photomask having substantially the same outer shape as the outer shape of the stamper A step of contacting and exposing to the photoresist layer to match the non-roughened area of the glass master, and a step of peeling off the photomask from the photoresist layer and developing the photoresist, Forming a conductive film on the developed photoresist layer; depositing an electroformed product on the conductive material to form an electroformed product; Characterized in that it comprises a step of ablating a region corresponding to the roughened regions of the electroformed member detached from the photoresist layer.

According to a fourth aspect of the present invention, there is provided a glass master for manufacturing a stamper, wherein one surface of the glass master has a rough surface portion and a mirror surface portion. It is characterized by being substantially the same as the outer shape of the photomask used for (1).

According to a fifth aspect of the present invention, there is provided a glass master for manufacturing a stamper, wherein the glass master has a rough surface portion and a mirror surface portion on one surface, and the outer shape of the mirror surface portion is determined when manufacturing the stamper. It is characterized by being substantially the same as the outer shape of the photomask used for (1).

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram for explaining a configuration of a glass master disk according to one embodiment of the present invention. The glass master 1 has, for example, a disk shape with a diameter of 500 mm and a thickness of 6 mm, and has a rough surface portion 2 and a mirror surface portion 3 on a surface on which a photoresist layer is formed. The mirror part 3
It is formed in substantially the same shape as the outer shape of a photomask described later, and the center of the mirror surface portion 3 is formed so as to be located at the center of the glass master 1.

A rough surface portion 2 is formed outside the mirror surface portion 3 of the glass master 1. The surface roughness of the rough surface portion 2 is selected depending on the thickness of a photoresist layer described later. That is, the rough surface portion 2 and the mirror surface portion 3 can be visually distinguished. When a photoresist layer is formed on the glass master 1 by spin coating, the film of the photoresist layer formed on the mirror surface portion 3 is formed. A surface roughness that does not significantly affect the thickness distribution is selected.

FIG. 2 is a diagram for explaining a process for manufacturing a glass master disk according to one embodiment of the present invention. In this embodiment,
The outer dimensions of the mask and photomask are 340 mm long and 2 mm wide.
70 mm rectangle. As shown in FIG. 2A, a mask 4 having a shape substantially the same as the outer shape of a photomask to be described later is brought into close contact with a mirror-polished surface of a glass master 1 whose one surface is mirror-polished. The mask 4 is installed such that the center of the mask 4 is located substantially at the center of the glass master 1. Aluminum oxide powder or the like is sprayed at a high pressure onto the glass master 1 on which the mask 4 is installed (sand blast method) to roughen the surface of the glass master 1 except for the area covered with the mask 4.

As shown in FIG. 2B, the area of the surface of the glass master 1 covered with the mask 4, that is, the area having substantially the same shape as the outer shape of the photomask described later remains as a mirror surface and the glass The area other than the area covered by the mask 4 on the surface of the master 1 is roughened. In the present embodiment, the surface roughening process is performed by the sand blast method.However, the present invention is not limited to this. The surface roughening process may be performed using sandpaper, steel wool, or the like, or ion etching or the like may be performed. The surface may be roughened by a method.

FIG. 3 is a view for explaining a process of manufacturing a stamper using a glass master disk according to one embodiment of the present invention. FIG. 3A shows a photoresist coating step. A glass master 1 having a rough surface portion 2 and a mirror surface portion 3 according to one embodiment of the present invention is washed and attached to a spin coater, and the rough surface portion 2 and the mirror surface portion 3 of the glass master disk 1 are spin-coated.
A photoresist layer 5 is formed on the surface on which is formed.
The boundary between the rough surface portion 2 and the mirror surface portion 3 can be visually identified through the photoresist layer 5.

FIG. 3B shows an exposure step. The photomask 6 on which the plurality of deflection patterns 7 are drawn is brought into close contact with the surface of the photoresist layer 5. In the photomask 6, a portion of the deflection pattern 7 transmits UV light 9 described later, and a region other than the deflection pattern 7 does not transmit the UV light 9. At this time, since the outer shape of the photomask 6 and the mirror surface portion 3 are substantially the same, the photomask 6 is brought into close contact with the surface of the photoresist layer 5 using the region where the mirror surface portion 3 is formed as an index. Since the center of the mirror surface portion 3 is located at the center of the glass master 1, the photomask 6 comes into close contact with a region where the thickness distribution of the photoresist layer 5 is uniform. Then, light (ultraviolet (UV) light) 9 having a wavelength to which the photoresist layer is exposed is exposed from the upper surface of the photomask 6. At this time, a region of the photoresist layer 5 corresponding to the deflection pattern 7 and a region not in contact with the photomask 6 are exposed.

FIG. 3C shows a developing step. The glass master 1 on which the exposed photoresist layer 5 is formed is attached to a developing device, the photoresist layer 5 is developed with a developing solution, and the developing solution is washed with pure water. At this time, FIG.
Photoresist layer 5 exposed to UV light 9 in step (b)
The region corresponding to the deflection pattern 7 is removed, and an unexposed portion 10 remains on the mirror surface portion 3 of the glass master 1. Further, a photoresist layer 5 formed on the rough surface portion 2 of the glass master 1 is formed.
Is an area that is not in contact with the photomask 6, and
It is exposed to light 9 and removed.

On the glass master 1 after the development step, only the unexposed portion 10 of the photoresist layer 5 in the region on the mirror surface portion 3 remains, and does not adhere to the region corresponding to the deflection pattern 7 of the photomask 6 and the photomask 6. The photoresist layer 5 in the region on the rough surface 2 is removed. Therefore,
The rough surface 2 of the glass master 1 is exposed.

FIG. 3D shows an electroforming process. The glass master 1 after the development process is attached to a sputtering device,
A conductive film such as chromium (Cr) or nickel (Ni) is formed on the surface of the glass master 1 on which the photoresist layer 5 is formed by a sputtering method. The glass master 1 on which the conductor film is formed is attached to an electroforming apparatus, and nickel electroforming is performed. Electroformed body 11 is formed on the conductor film. In the present embodiment, since the outer peripheral portion (rough surface portion 2) of the glass master 1 is rough, the electroformed body 11 is moved during the electroforming process.
Hard to peel off from

FIG. 3E shows a peeling step. Electroformed body 1
When the thickness of the glass master 1 is about 0.3 mm, the electroforming step is finished, the glass master 1 is taken out of the electroforming apparatus, and the electroformed body 11 is removed.
From the glass master 1. The pattern of the unexposed portion 10 corresponding to the deflection pattern 7 of the photomask 6 is transferred to the electroformed body 11.

FIG. 3F shows a stamper processing step.
The electroformed body 11 peeled from the glass master 1 is polished on the back surface and further processed into a predetermined outer shape so that the rough surface portion 2 does not remain, and a stamper 12 is obtained.

As another embodiment, if the mask 4, the photomask 6, and the stamper 12 have the same outer shape,
The outer shape of the stamper can be processed using the boundary line between the rough surface portion 2 and the mirror surface portion 3 of the glass master 1 transferred to the electroformed body 11 as an index. That is, in the electroforming step, areas corresponding to the rough surface portion 2 and the mirror surface portion 3 of the glass master 1 are transferred to the electroformed body 11. The outer shape of the mirror surface portion 3 is a stamper 12
Of the electroformed body 1 using the boundary line of the region corresponding to the rough surface portion 3 and the mirror surface portion 2 of the electroformed body 11 as an index.
Cut off the outer periphery of 1. According to the stamper manufacturing method of the present embodiment, when obtaining the stamper 12, the size of the outer shape can be easily determined and processed.

[0034]

According to the present invention, there are provided a glass master, a method of manufacturing a glass master, and a method of manufacturing a stamper, in which the alignment of a photomask is easy and the electroformed body is hardly peeled off during the electroforming process. can do.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a configuration of a glass master disk according to one embodiment of the present invention.

FIG. 2 is a diagram illustrating a process of manufacturing a glass master disk according to one embodiment of the present invention.

FIG. 3 is a diagram illustrating a process of manufacturing a stamper using a glass master according to one embodiment of the present invention.

FIG. 4 is a schematic view showing a conventional manufacturing process of a light guide having an uneven portion as a deflection element on its surface.

FIG. 5 is a schematic view showing the configuration of the glass master after the development step of FIG. 4 as viewed from above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass master 2 Rough surface part 3 Mirror surface part 4 Mask 5 Photoresist layer 6 Photomask 7 Deflection pattern 8 Exposure part 9 UV light 10 Unexposed part 11 Electroformed body 12 Stamper 21 Glass master 22 Photoresist layer 23 Photomask 24 Exposure part 25 Unexposed part 26 Electroformed body 27 Stamper 28 Light guide

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 9/00 G03F 9/00 Z

Claims (5)

[Claims] A step of bringing a mask having substantially the same outer shape as that of a photomask into close contact with the surface of the glass master; and a step of roughening an area of the surface of the glass master other than an area where the mask is in close contact. A method for manufacturing a glass master, comprising: 2. A step of bringing a mask having substantially the same outer shape as that of a photomask into close contact with the surface of the glass master, and a step of roughening an area of the surface of the glass master other than the area where the mask is in close contact. Forming a photoresist layer on the surface of the glass master from which the mask has been peeled off; and exposing the photomask to the photoresist layer in close contact with the non-roughened region of the glass master. Removing the photomask from the photoresist layer and developing the photoresist layer; forming a conductor film on the developed photoresist layer; depositing an electroformed product on the conductor Forming an electroformed body, and removing the electroformed body from the photoresist layer and processing the electroformed body into a desired outer shape. Stamper manufacturing method. 3. A method of manufacturing a stamper, comprising: bringing a mask having substantially the same outer shape as that of the stamper into close contact with the surface of the glass master; excluding a region of the surface of the glass master where the mask is in close contact. A step of roughening an area; a step of forming a photoresist layer on the surface of the glass master from which the mask has been peeled off; and a step of forming a photomask having substantially the same outer shape as the outer shape of the stamper on the rough surface of the glass master. Exposing the photoresist to the photoresist layer so as to coincide with the unmodified region, exposing the photomask from the photoresist layer, and developing the photoresist; and A step of forming a conductor film; a step of forming an electroformed body by depositing an electroformed product on the conductor; and a step of forming the electroformed body by the photoresist layer. Method of manufacturing a stamper, characterized in that it comprises the step of ablating et peeled area corresponding to the roughened regions of the electroformed member. 4. A glass master for manufacturing a stamper, comprising: a rough surface portion and a mirror surface portion on one surface, wherein an outer shape of the mirror surface portion is substantially the same as an outer shape of a photomask used when manufacturing the stamper. A glass master disc, which is identical. 5. A glass master for manufacturing a stamper, comprising: a rough surface portion and a mirror surface portion on one surface, wherein an outer shape of the mirror surface portion is substantially equal to an outer shape of a photomask used when manufacturing the stamper. A glass master disc, which is identical.