Method of metal mask and manufacturing method of metal mask

A computer-readable storage medium in which computer programs are stored, wherein the computer programs implement, when executed by a processor, the following steps:

• calculating amounts of deformations of the metal mask in two directions perpendicular to each other based on a stretching force of the metal mask in use and properties of the deformations of the metal mask in the two directions;
• and
• calculating compensation amounts for the deformations of the metal mask in the two directions by compensation amounts for the deformations, which are identical and opposite to the amounts of the deformations of the metal mask in the two directions, respectively, and manufacturing the metal mask based on results of the calculating compensation amounts,
• wherein the computer programs further implement, when executed by a processor, the following steps:
• determining design dimensions of the metal mask;
• acquiring material properties of a material for manufacturing the metal mask;
• and
• calculating the properties of the deformations of the metal mask in the two directions based on the design dimensions of the metal mask and the material properties of the material for manufacturing the metal mask,
• wherein the design dimensions of the metal mask comprise a length, a width and a thickness of the metal mask, a cross-sectional area of an opening in the metal mask, a lateral interval and a longitudinal interval between two adjacent openings in the metal mask;
• and
• the material properties of the material for manufacturing the metal mask comprise Young's modulus and Poisson's ratio,
• wherein the computer programs further implement, when executed by a processor, calculating the properties of the deformations of the metal mask in the two directions:
• Young's modulus Ex of the metal mask in a stretching direction, which is:
• Ex=E×e/(a+e);
• Young's modulus Ey of the metal mask in a direction perpendicular to the stretching direction, which is:
• Ey=E×b/(c+b);
• and
• Poisson's ratio v of the metal mask, which is:
• v=v0×l/w×((a+e)*(b+c)/(a·b))1/2,
• wherein the width of the metal mask is w, the length of the metal mask is l, the cross-sectional area of the opening is a·b, the lateral interval is e, the longitudinal interval is c, the material for manufacturing the metal mask has Young's modulus E and Poisson's ratio v0,
• wherein, the stretching force applied to the metal mask is F, and the properties of the deformations further comprise:
• a cross-sectional normal stress σx of the metal mask in the stretching direction, which is:
• σx=F/(w×t);
• a cross-sectional elongation Δl of the metal mask in the stretching direction, which is:
• Δl=±F×l/(Ex×w×t);
• a cross-sectional normal strain εx of the metal mask in the stretching direction, which is:
• εx=Δl/l=σx/Ex;
• and
• a relationship between the normal strain εx of the metal mask in the stretching direction and a normal strain εy of the metal mask in a direction perpendicular to the stretching direction, which is:
• εx=−v×εy,
• wherein, t is the thickness of the metal mask,
• wherein the computer programs further implement, when executed by a processor, the following:
• taking a correction parameter C1 into account, the properties of the deformations further comprise:
• the cross-sectional normal stress σx of the metal mask in the stretching direction, which is:
• σx=F/(w×C1×t);
• the cross-sectional elongation Δl of the metal mask in the stretching direction, which is:
• Δl=±F×l/[Ex×(w×C1×t)];
• the cross-sectional normal strain εx of the metal mask in the stretching direction, which is:
• εx=Δl/l=σx/Ex;
• and
• the relationship between the normal strain εx of the metal mask in the stretching direction and the normal strain εy of the metal mask in the direction perpendicular to the stretching direction, which is:
• εx=−v×εy,
• wherein the correction parameter C1 is related to an etching process for forming the opening, two etching processes are performed on the metal mask from front and reverse sides, respectively, and a size of the opening along a direction parallel to a plane in which the metal mask is located first increases and then decreases along a thickness direction of the metal mask,
• wherein a compensation amount for the deformation of the metal mask in the stretching direction is:
• T.R.x=Δl/l%=σx/Ex%;
• and
• a compensation amount for the deformation of the metal mask in the direction perpendicular to the stretching direction is:
• T.R.y=Δw/w%=εy%=−T.R.x/v%
• wherein the computer programs further implement, when executed by the processor, the following steps:
• obtaining values of a long side and a short side of the metal mask during manufacturing, according to the compensation amount for the deformation of the metal mask in the stretching direction and the compensation amount for the deformation of the metal mask in the direction perpendicular to the stretching direction, respectively, so that the opening in the metal mask correspond to a corresponding location on a back panel of thin film transistors when the metal mask is stretched and deformed, and
• forming the opening in the metal mask by two etching processes performed on the metal mask from front and reverse sides of the metal mask, respectively, such that an inclination angle of the opening with respect to the plane, in which the metal mask is located, is formed.