Method for manufacturing deposition mask, method for manufacturing display device and deposition mask

1. A method for manufacturing a vapor deposition mask including a mask portion that is formed from a metal plate made of an iron-nickel alloy and has a plurality of mask holes, the method comprising:

sandwiching a plastic layer between a 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 a mask portion including a plurality of mask holes from the metal plate;

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 a 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; and

peeling off the plastic layer and the glass substrate from the mask portion.

2. The method for manufacturing a vapor deposition mask according to claim 1 , wherein

peeling off the plastic layer and the glass substrate includes

peeling off the glass substrate from the plastic layer by irradiating an interface between the plastic layer and the glass substrate with a laser beam having a wavelength that passes through the glass substrate and is absorbed by the plastic layer, and

peeling off the plastic layer from the mask portion by dissolving the plastic layer using a chemical solution after peeling off the glass substrate from the plastic layer.

3. The method for manufacturing a vapor deposition mask according to claim 2 , wherein at the wavelength of the laser beam, the glass substrate has a higher transmittance than the plastic layer.

4. The method for manufacturing a vapor deposition mask according to claim 3 , wherein

the wavelength of the laser beam is between 308 nm and 355 nm inclusive,

the transmittance of the glass substrate at the wavelength is greater than or equal to 54%, and

the transmittance of the plastic layer at the wavelength is less than or equal to 1%.

5. The method for manufacturing a vapor deposition mask according to claim 1 , wherein

the mask frame is made of an iron-nickel alloy, and

a ratio of a thickness of the mask frame to a thickness of the mask portion is greater than or equal to 2.

6. The method for manufacturing a vapor deposition mask according to claim 5 , wherein

the thickness of the mask frame is between 50 μm and 200 μm inclusive,

the thickness of the mask portion is between 3 μm and 5 μm inclusive, and

forming the mask portion includes forming the mask holes such that 700 or more and 1,000 or less mask holes are arranged per inch in a direction along a surface of the mask portion.

7. The method for manufacturing a vapor deposition mask according to claim 1 , wherein

joining the metal plate to the glass substrate with the plastic layer in between includes joining the metal plate having a thickness of greater than or equal to 10 μm to the glass substrate with the plastic layer in between, and

the method further comprises etching the metal plate before the mask portion is formed from the metal plate to reduce a thickness of the metal plate to half or less of a thickness of the metal plate before etching.

8. The method for manufacturing a vapor deposition mask according to claim 1 , wherein the plastic layer is made of polyimide.

9. The method for manufacturing a vapor deposition mask according to claim 1 , wherein

the metal plate includes a first surface and a second surface,

the method further comprises etching the metal plate from the first surface before joining the metal plate to the glass substrate,

joining the metal plate to the glass substrate includes joining a surface obtained after the first surface is etched to the glass substrate with the plastic layer in between, and

the method further comprises etching the metal plate from the second surface after the metal plate is joined to the glass substrate.