Backside warpage control structure and fabrication method

摘要

Through vias extend through a substrate between a frontside surface and a backside surface, the through vias comprising active surface ends at the frontside surface. A frontside redistribution structure is coupled to the active surface ends, the frontside redistribution structure exerting force on the frontside surface, e.g., due to a difference in the thermal coefficient of expansion (TCE) between the frontside redistribution structure and the substrate. To prevent warpage of the substrate, a backside warpage control structure is coupled to the backside surface of the substrate. The backside warpage control structure exerts an equal but opposite force to the force exerted by the frontside redistribution structure thus avoiding warpage of the substrate.