Thermo-stable coating die design method and apparatus

A method of designing and the resulting thermally stable heated coating die apparatus, the die apparatus including a die having a die geometry and a heating system with heaters and temperature sensors. The method and resultant apparatus provides minimized temperature gradients, flat die lip faces in a die to roll plane and a flat die in a plane perpendicular to die flat lip faces and parallel to substrate width. The method optimizes simultaneously: die geometry, placement of the heaters, placement of temperature sensors, and shielding from operating conditions, using heat transfer and structural numerical modeling and statistical analysis while considering die functionality characteristics, minimum increment of temperature measurement and control accuracy related to minimum acceptable deviation from flatness, coating die material of construction relative to thermo-structural material properties, and desirable coating die material properties.