Metal plate, method of manufacturing metal plate, and method of manufacturing deposition mask by use of metal plate

A metal plate to be used for manufacturing a deposition mask by forming a plurality of through-holes in the metal plate,

• wherein:
• the through-holes of the deposition mask are formed by etching the elongated metal plate,
• when a plurality of samples are taken out from the metal plate, a distance between two measurement points on each sample, which is measured before a heat treatment, is referred to as L1, a distance therebetween which is measured after the heat treatment is referred to as L2, and a thermal recovery rate F of each sample is defined by the following expression:
• F={(L1−L2)/L1}×106 (ppm), the following conditions (1) and (2) are satisfied:
• (1) 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;
• the samples are obtained by cutting at least one sample metal plate, which is obtained by cutting the metal plate along a width direction of the metal plate, into two or more along a longitudinal direction of the metal plate;
• the two measurement points on the sample are aligned along the longitudinal direction of the metal plate;
• the heat treatment includes a first step of increasing a temperature of each sample from 25° C. to 300° C. for 30 minutes, a second step of keeping the temperature of each sample at 300° C. for 5 minutes, and a third step of decreasing the temperature of each sample from 300° C. to 25° C. for 60 minutes;
• and
• the dispersion of the thermal recovery rates is a value obtained by multiplying 3 to a standard deviation of the thermal recovery rates of the respective samples.

A method of manufacturing a deposition mask having a plurality of through-holes formed therein, comprising:

• a step of preparing a metal plate;
• a resist pattern forming step of forming a resist pattern on the metal plate;
• and
• an etching step of etching an area of the metal plate, which is not covered with the resist pattern, to form recesses in the metal plate, the recesses being configured to define the through-holes;
• wherein:
• when a plurality of samples are taken out from the metal plate, a distance between two measurement points on each sample, which is measured before a heat treatment, is referred to as L1, a distance therebetween which is measured after the heat treatment is referred to as L2, and a thermal recovery rate F of each sample is defined by the following expression:
• F={(L1−L2)/L1}×106 (ppm), the following conditions (1) and (2) are satisfied:
• (1) 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;
• the samples are obtained by cutting at least one sample metal plate, which is obtained by cutting the metal plate along a width direction of the metal plate, into two or more along a longitudinal direction of the metal plate;
• the two measurement points on the sample are aligned along the longitudinal direction of the metal plate;
• the heat treatment includes a first step of increasing a temperature of each sample from 25° C. to 300° C. for 30 minutes, a second step of keeping the temperature of each sample at 300° C. for 5 minutes, and a third step of decreasing the temperature of each sample from 300° C. to 25° C. for 60 minutes;
• and
• the dispersion of the thermal recovery rates is a value obtained by multiplying 3 to a standard deviation of the thermal recovery rates of the respective samples.