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.

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.