Semiconductor Device and Method of Forming RDL Hybrid Interposer Substrate

A semiconductor device has a first substrate and a first electrical component disposed over the first substrate. The first electrical component has a second substrate, and redistribution layer formed over the second substrate. The first electrical component is disposed over the redistribution layer. The heat spreader is disposed over the first electrical component. A heat spreader is disposed over the first electrical component. The heat spreader has a first horizontal portion, second horizontal portion vertically offset from the first horizontal portion, and an angled portion connecting the first horizontal portion from the second horizontal portion. The second horizontal portion attaches to a surface of the first substrate proximate to a first side of the first electrical component. The heat spreader attaches to the first substrate proximate to a first side of the first electrical component and remains open proximate to a second side of the first electrical component.