A method of forming a semiconductor device includes preparing a first semiconductor die package with conductive elements embedded in a molding compound, wherein the conductive elements are exposed on a surface of the molding compound. A top surface of the conductive elements is above or co-planar with a top-most surface of the molding compound. The method further includes providing a second semiconductor die package; and bonding the conductive elements of the first semiconductor die package to contacts on the semiconductor die package.