Vapor deposition mask base material, vapor deposition mask base material manufacturing method, and vapor deposition mask manufacturing method

A method for manufacturing a vapor deposition mask substrate, comprising a metal sheet that has a shape of a strip and is configured to be etched to include a plurality of holes so that the metal sheet is used to manufacture a vapor deposition mask, the method comprising:

• obtaining the metal sheet by rolling a base material, wherein
• the metal sheet has shapes that are taken along a longitudinal direction of the metal sheet at different positions in a width direction of the metal sheet and differ from one another, each of the shapes being an undulated shape including protrusions and depressions repeating in the longitudinal direction of the metal sheet,
• a length in the longitudinal direction of a surface of the metal sheet is a surface distance,
• a minimum value of surface distances at different positions in the width direction of the metal sheet is a minimum surface distance,
• a ratio of a difference between a surface distance at each of the different positions in the width direction of the metal sheet and the minimum surface distance to the minimum surface distance is an elongation difference ratio, and
• obtaining the metal sheet includes rolling the base material such that:
• the elongation difference ratio in a center section in the width direction of the metal sheet is less than or equal to 3×10−5;
• the elongation difference ratios in two edge sections in the width direction of the metal sheet are less than or equal to 15×10−5;
• and
• the elongation difference ratio in at least one of the two edge sections in the width direction of the metal sheet is less than the elongation difference ratio in the center section in the width direction of the metal sheet.

A method for manufacturing a vapor deposition mask, the method comprising:

• forming a resist layer on a metal sheet having a shape of a strip;
• and
• forming a plurality of holes in the metal sheet by etching using the resist layer as a mask to form a mask portion, wherein
• the metal sheet has shapes that are taken along a longitudinal direction of the metal sheet at different positions in a width direction of the metal sheet and differ from one another, each of the shapes being an undulated shape including protrusions and depressions repeating in the longitudinal direction of the metal sheet,
• a length in the longitudinal direction of a surface of the metal sheet is a surface distance,
• a minimum value of surface distances at different positions in the width direction of the metal sheet is a minimum surface distance,
• a ratio of a difference between a surface distance at each of the different positions in the width direction of the metal sheet and the minimum surface distance to the minimum surface distance is an elongation difference ratio, and
• the metal sheet is obtained such that:
• the elongation difference ratio in a center section in the width direction of the metal sheet is less than or equal to 3×10−5;
• the elongation difference ratios in two edge sections in the width direction of the metal sheet are less than or equal to 15×10−5;
• and
• the elongation difference ratio in at least one of the two edge sections in the width direction of the metal sheet is less than the elongation difference ratio in the center section in the width direction of the metal sheet.