A method for reducing warpage on an organic substrate. The method includes: preparing an organic substrate, which includes (i) a core layer having an organic material, (ii) a first buildup layer on a front surface of the core layer, and (iii) a second buildup layer on a back surface of the core layer, measuring warpage of the organic substrate, calculating a thickness of a correction layer for reducing the warpage using properties of constituent materials including the coefficient of thermal expansion (CTE) and the Young's modulus of the core layer, and CTEs and the Young's modulus of the first and the second buildup layers, and forming at least one correction layer having the thickness on at least one part of surfaces of the first buildup layer and the second buildup layer. A system and an organic substrate is also provided.