JPS6283336A - Production of microlens array - Google Patents

Abstract

PURPOSE:To easily produce the titled microlens array by forming many circular resist patterns on optical glass, etching the glass to obtain columnar protrusions, then removing the resist and again etching the glass to form the protrusion into a spherical shape. CONSTITUTION:The photoresist 2 is coated on the surface of a glass sheet 3 and a photomask 1 wherein many circular light-shielding parts are arranged is provided thereon. Then UV rays are irradiated, the photomask is removed and the glass is again etched to form many circular protrusions on the glass sheet. The photoresist 2 is removed, etching is again carried out, the angles of the columnar protrusions 5 are rounded off along with the glass sheet to obtain a spherical shape 6. Then the surface is polished with a soft brush, etc., and the planar microlens array wherein many convex lenses are arranged is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a microlens array in which a large number of minute convex lenses are arranged on a flat glass.

[Prior Art] Microlens has recently attracted attention as a constituent material for various optical components for optical communications, and microlens arrays, in which a large number of these lenses are arranged, are used as transfer lenses in optical systems for copiers and mini-faxes. This contributes to the miniaturization of devices.

The conventional method for creating a microlens array was to arrange several hundred rod-shaped lenses with a diameter of about 11 in two or three rows to form an array. First, a metal film 11 is vapor-deposited on a sheet of flat glass 10, and a large number of holes 12 are arranged in this metal film using photophosphorography technology. The holes in the metal film are immersed in a molten cylinder containing highly refractive ions such as
A flat plate microlens is attracting attention, which is made by diffusing ions through a glass plate 2 and arranging microlenses each having a semicircular spherical high refractive ion diffusion part 13 on a flat glass plate as shown in FIG. According to this method, not only does it not require multiple processes such as arranging, gluing, and fixing a large number of rod lenses, but it also uses the same futrinography technology used in the integrated circuit manufacturing process to achieve high precision. Lenses can be arrayed all at once.

[Problems to be solved by the invention] However, in order to create a lens with small aberrations, for example, it is necessary to strictly control the shape of the ion diffusion part and the ion concentration distribution, and sometimes the voltage It is also necessary to forcibly diffuse and import ions by applying ions, so it is difficult to say that this method is necessarily good in terms of productivity, as it requires some ingenuity in the equipment.

The present invention improves the problems of the conventional method of manufacturing a flat microlens array as described above, and provides a microlens array in which lenses with large numerical apertures and diameters are arranged.

[Means for solving the problem] Therefore, in the present invention, a large number of circular resist patterns are formed using a 7-photoresist on optical glass, and after forming cylindrical protrusions in an etching process, further resist is applied. After removal, etching is continued again to chemically remove the corners of the cylindrical portion to make it spherical, and a convex lens is obtained through a polishing process. Hereinafter, the present invention will be described in detail using specific examples along with the drawings.

[Example] As shown in FIG.
A photomask 1 having a large number of circular light shielding parts arranged thereon is further placed. Next, after irradiating ultraviolet rays through the photomask 1, the photomask is removed and the glass plate is etched to form a large number of cylindrical protrusions on the glass plate as shown in FIG. As another example, as shown in FIG. 3, by depositing a large number of circular metal films 4 on a glass plate and etching the glass, a large number of cylindrical protrusions as shown in FIG. 4 are formed on the glass surface. Arranged. When the photoresist 2 or the metal film 4 is removed from the glass plate that has been etched to some extent, a glass plate with a large number of cylindrical protrusions 5 arranged as shown in FIG. 5 or 6 is obtained. Here, etching is performed again, and the corners of the cylindrical protrusion 5 are removed together with the glass plate to make the cylindrical protrusion spherical 6, as shown in FIG. Next, by polishing the surface of this glass plate using a soft brush or a soft puff, it becomes possible to create a flat plate microlens array in which a large number of convex lenses are arranged as shown in FIG. Also the 7th
In the etching process shown in the figure, rapidly flowing the etching solution along the glass surface is effective in selectively removing the corners of the protrusions 5.

[Effect of the Invention 1] According to the present invention, a microphone lens with rounded protrusions can be easily manufactured.

[Brief explanation of drawings]

Figure 1 shows the method for manufacturing a microlens array according to the present invention.
Figure 2 is a cross-sectional view of the process in which a photomask is placed on the surface of a glass plate to illuminate ultraviolet rays; Figure 2 is a cross-sectional view of the state where the photomask has been removed and etched; Figure 3 is a cross-sectional view of the process in which the metal 4 is a sectional view of the etched version of the one shown in FIG. 3, and FIGS. 5 and 6 show a large number of cylindrical text parts after removing the photoresist or metal evaporation film. 7 is a sectional view showing a state in which a cylindrical protrusion is processed into a spherical shape. FIG. 8 is a perspective view of a flat microlens array according to the method of the present invention. The figure is a sectional view of a conventional method for manufacturing a flat plate microlens array, and FIG. 10 is a perspective view of the microphone lens array shown in FIG. 1... Photomask, 2... Photoresist, 3.
...Glass plate, 4...Metal vapor deposited film, 5...Cylindrical protrusion, 6...Spherical protrusion. Applicant Hoya Co., Ltd. Agent Masayuki Asakura Figure 1 Figure 6 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] After arranging an array of circular photomask patterns on the surface of a glass plate coated with photoresist and irradiating ultraviolet rays through the photomask patterns, or forming a resist pattern by depositing a circular metal vapor deposition film. ,
Etching a glass plate to arrange cylindrical protrusions on the glass plate, removing the resist or metal vapor deposition film, and repeating etching again to transform the cylindrical protrusions into a spherical shape to form a convex lens. A method for manufacturing a microlens array characterized by.