SU1675836A1 - Method for making dies for manufacture of lense rasters - Google Patents

Abstract

The invention relates to a method for manufacturing a matrix for the manufacture of lens rasters. The method allows to expand the technological capabilities and improve the quality of the matrices, for which cyclically form the relief of lens elements on a metal substrate by using a positive photoresist as a photosensitive layer and multiple exposures onto successively applied layers of photoresist images of a periodic binary structure with a stepped reduced duty cycle.

Description

The invention relates to the manufacture of lens rasters used in optical devices, in the printing industry, in devices for obtaining spatial and integral photographs, and the like.

The aim of the invention is to expand the technological capabilities of the method and improve the quality of lenticular rasters.

The method is carried out as follows.

The relief of lens elements on the substrate is obtained by creating on the metal substrate an image of periodic lens elements of the raster formed by a positive photoresist, building up a metal layer and re-creating the image of lens elements by a positive photoresist, and the image is characterized by a reduced porosity of the elements of the periodic binary structure, followed by increasing these operations to create a profile lenses with a given accuracy, smoothing the surface of the relief electrochemistry skim polishing layer and applying a low-melting metal or alloy, cooling to solidify it.

Example. A positive FP-383 photoresist was applied to the polished, cleaned from contamination surface of a plate of brass alloy LS-59 on a centrifuging installation and dried at 100 ° С for 10 minutes. An image of a binary structure having areas that are transparent to light rays in the form of hexagonally arranged disks with a diameter of 70 μm and in increments of 75 μm is placed on a photoresist film. Open in the photoresist round windows and oak t the resulting photoresistive image for 15-20 minutes at 150 ° C. Decapitate the surface of the exposed metal to remove the oxide film in a 10% solution of nitric acid and build up a layer of copper 3 µm thick in the electrolyte composition, g / l:

CuS045H20210

H2SO4 (conc.) 50

WITH

WITH

sc

but

00

00

about

Brightener

BESM0,4

NaCI0.01

Copper anode.

Electrolysis mode: temperature 18-25 ° С, current density 2-3 A / dm2. The electrolysis time is chosen experimentally in such a way as to obtain a copper layer of a given thickness.

The surface of the blank is washed with water, dried and the next layer of photoresist is applied, on which the image of the binary structure is placed with a reduced duty cycle, i.e. The only difference is that the diameter of the transparent discs is 56 microns. and this structure is placed in such a way that the centers of its transparent disks strictly coincide with the centers of the copper disks of the previous layer. Then, all operations are repeated, after which a third layer of photoresist is applied, in which, using the described method, holes with a diameter of 29 µm are formed, which are located exactly in the center of the copper disks of the previous row (for a more accurate approximation of the profile of lens elements of a given curvature of such alternating operations of applying a photoresistive mask and building the metal layer should not be 3, but much more; in this case, binary structures are used, in which the step of decreasing the diameter of transparent disks tends to the minimum value, increases the number of layers of expandable metal is reduced, their thickness is reduced).

The photoresist is removed in a 20% sodium hydroxide solution and, after washing, the model is treated in a polishing electrolyte with the following composition: CgO2 SO2 / liter of 140 ml / l.

Electropolishing mode: solution temperature 30-40 ° C, anodic current density 20 A / dm2, polishing time 1 min.

A relief is obtained on a metal substrate for electrolytic buildup of the matrix. To improve the quality of the matrix, a layer of tin in the electrolyte of the composition, g / l, is applied to the relief made:

SnCl240

HCI0,5

NaF40

Sintanol1

Electrolysis mode: the electrolyte temperature is 18–25 ° C, the cathode current density is 2 A / dm 2, the deposition time is 15–20 min. The time of deposition of tin is chosen experimentally so that the thickness of the enlarged layer is at least 1 µm (since below this value the melting of tin is difficult) and not more than the height of one copper layer, i.e. in this case

micron (as an excess of the melt can lead to distortion of the lens-raster relief). The billet is dried and immersed for 0.2-0.3 min in glycerol at 237-277 ° C. After the tin coating has melted, the substrate with the relief is left in a strictly horizontal position until the melt is completely solidified.

For electrolytic buildup

Matrices 0 use an electrochemical nickel plating bath in which the nickel plate serves as the anode, the electrolyte has the following composition, g / l:

NiSCM7H20180-200

5NaaSCM 10H2060-75

NZOZO25-30

NaCI10-15

at pH 5-5.5.

Electrolysis mode: temperature 180–25 ° С, current density 1-3 A / dm2. The electrolysis is carried out for 2-3 hours to obtain a nickel layer of 80-100 microns thick. The resulting matrix is determined from the substrate with a relief using a sharp knife, washed

5 with water and dried.

The resulting matrix serves to make periodic lens rasters with a lens diameter of 70 µm and a pitch of 75 µm.

0

Claims (1)

The invention The method of obtaining a matrix for the manufacture of lenticular rasters, consists in forming a raster lens elements on the substrate by exposing an image on a substrate coated with a photosensitive layer, the binary structure of which corresponds to the spatial distribution of the lenses 0 elements, applying a metal layer to areas corresponding to the lens elements of the substrate, wetting the relief with a melt of a low-melting metal, cooling it before curing, electrolytic deposition of the metal layer on the resulting relief, and its separation from the surface of the relief way and quality improvement 0 matrices, a positive photoresist is used as a photosensitive layer, and a set of periodic binary structures of different porosity is used as the exposed image; 5 metal layer is carried out cyclically, while before each exposure they align the raster elements and the binary structure of a stepwise reduced duty cycle in relation to the previous one.