Metal plate

Abstract

The object of the present invention is to provide a metal plate capable of manufacturing a deposition mask in which dispersion of positions of through-holes is restrained. A thermal recovery rate is defined as parts per million of a difference a distance between to measurement points on a sample before a heat treatment and a distance therebetween after the heat treatment, relative to the distance therebetween before the heat treatment. In this case, an average value of the thermal recovery rates of the respective samples is not less than −10 ppm and not more than +10 ppm, and (2) a dispersion of the thermal recovery rates of the respective samples is not more than 20 ppm.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. application Ser. No. 15 / 026,009, filed Mar. 30, 2016, which in turn is the National Stage of International Application No. PCT / 3P2014 / 075168, filed Sep. 24, 2014, the entireties of which are incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to a metal plate for use in manufacturing a deposition mask with a plurality of through-holes formed therein. In addition, the present invention relates to a method of manufacturing the metal plate. In addition, the present invention relates to a method of manufacturing the mask with a plurality of through-holes formed therein, by use of the metal plate.BACKGROUND OF THE INVENTION[0003]A display device used in a portable device such as a smart phone and a tablet PC is required to have high fineness, e.g., an image density not less than 300 ppi. In addition, there is increasing demand that the portable device is applicab...

AI Technical Summary

Benefits of technology

The present invention provides a method for manufacturing a deposition mask with reduced thickness and improved positioning precision of a deposition material. The method includes reducing the strain in the metal plate used for manufacturing the deposition mask and increasing the hardness of the resist film. The restraint on the strain can be achieved by increasing the reduction ratio during the manufacture of the metal plate and heat treatment after rolling. The reduced thickness of the deposition mask can be achieved by reducing the remaining stress in the metal plate, which results in a reduction of the dimension of the metal plate. The improved positioning precision of the deposition material can be achieved by improving the dimensional precision and positional precision of the through-holes in the deposition mask.

Problems solved by technology

Namely, the deposition near the wall surface of the through-hole of the deposition mask may become unstable.

Thus, when this deposition mask is used for forming pixels of an organic EL display device, dimensional precision of each pixel and positional precision thereof lower, which lowers luminous efficiency of the organic EL display device.

When a metal is rolled, strain occurs in the rolled metal.

Even if the metal is heat-treated such as annealed after being rolled, it is not easy to completely remove the strain for a short period of time.

In addition, there is a possibility that the degree of remaining strain inside the metal plate changes in the width direction of the metal plate.

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