Metal mask structure

A metal mask structure, comprising:

• a plate having a front surface and a back surface;
• and
• a plurality of slits extending along a first direction and respectively including a first opening formed on the front surface and a second opening formed on the second surface, wherein the first opening communicates with the second opening to penetrate through the plate,
• wherein a first longitudinal length of the first opening on the front surface and parallel to the first direction is less than a second longitudinal length of the second opening on the back surface and parallel to the first direction, the first opening has a first end and a second end opposite to each other on the first longitudinal length, and the second opening has a third end and a fourth end on the second longitudinal length corresponding to the first end and the second end, respectively,
• wherein a first distance between the first end and the third end projected on the front surface parallel to the first direction is less than or equal to 200 μm, and
• wherein a maximum width of the second opening on the back surface and perpendicular to the first direction is defined as an extended width, a width of the third end of the second opening on the back surface and perpendicular to the first direction is a second end width, and the second end width is less than or equal to the extended width.