An integrated circuit (IC) package includes a first substrate; a second substrate disposed over the first substrate; a plurality of connectors disposed between the first and second substrates such to electrically couple the first and second substrate; a constraint layer disposed over the first and second substrates such that a cavity is formed between the constraint layer and the first substrate; and a molding material disposed within the cavity and extending through the constraint layer. The constraint layer has a top surface and an opposing bottom surface and the molding material extends from the top surface to the bottom surface of the constraint layer.

Described implementations provide wireless, surface mounting of at least two semiconductor die on die attach pads (DAPs) of the semiconductor package, where the at least two semiconductor die are electrically connected by a clip. A stress buffer layer may be provided on the clip, and a heatsink may be provided on the stress buffer layer. The heatsink may be secured with an external mold material.