The invention claimed is:
1. A vapor deposition mask comprising:
a sheet-shaped mask portion made of an iron-nickel alloy and having a contact surface, which is configured to be in contact with a vapor deposition target, and a non-contact surface, which is opposite to the contact surface, wherein the mask portion includes a plurality of mask holes each extending from a first opening, which is located in the non-contact surface, to a second opening, which is located in the contact surface, and the second opening is smaller in size than the first opening; and
a mask frame that has a welding mark welded to the non-contact surface, has a higher rigidity than the mask portion, and is in a shape of a frame surrounding the mask holes,
the mask portion is formed by peeling off a plastic layer and a glass substrate from the mask portion after making the welding mark in a state where the glass substrate is joined to the contact surface with the plastic layer,
the welding mark is located on the non-contact surface opposite to the contact surface that follows the surface of the glass substrate.
2. The vapor deposition mask according to claim 1 , wherein
the thickness of the mask portion is between 1 μm and 15 μm inclusive.
3. The vapor deposition mask according to claim 1 , wherein
the vapor deposition mask has a plurality of mask portions,
the mask portion is one of the plurality of mask portions,
each mask portion is welded to the mask frame.
4. A method for manufacturing the vapor deposition mask according to claim 1 , the method comprising:
sandwiching the plastic layer between the glass substrate and a metal plate made of an iron-nickel alloy and joining the metal plate to the glass substrate with the plastic layer in between;
forming the mask portion including the plurality of mask holes from the metal plate joined to the glass substrate;
joining a surface of the mask portion that is opposite to a surface of the mask portion that is in contact with the plastic layer to the mask frame, which has a higher rigidity than the mask portion and is in a shape of a frame surrounding the mask holes of the mask portion by irradiating a portion in the mask portion which is in contact with the mask frame through the glass substrate and the plastic layer with a laser beam to weld the mask frame to the mask portion and make a welding mark; and
peeling off the plastic layer and the glass substrate from the mask portion which is joined to the mask frame.