US Patent 10595399 Method of reducing warpage of an organic substrate

An organic substrate includes a core layer including organic materials; a first buildup layer on a top surface of the core layer; a second buildup layer on a bottom surface of the core layer; and at least one correction layer formed on at least one part of surfaces of the first buildup layer and the second buildup layer, wherein the correction layer has a thickness which has been calculated 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 for reducing warpage of the organic substrate.