A package according to an embodiment includes a first device package and a fan-out RDL disposed over the first device package. The fan-out RDL extends past edges of the first device package. The first device package comprises a first die having a first redistribution layer (RDL) disposed on a first substrate, a second die having a second RDL disposed on a second substrate, an isolation material over the first die and extending along sidewalls of the second die, and a conductive via. The first RDL is bonded to the second RDL, and the first die and the second die comprise different lateral dimensions. At least a portion of the conductive via extends from a top surface of the isolation material to contact a first conductive element in the first RDL.