Patent ID: 7585700

Claim:
A method for manufacturing a ball grid array package stack, the method comprising: forming a lower ball grid package that has a foldable circuit substrate with a first substrate portion, a second substrate portion, and a third substrate portion, comprising: positioning an integrated circuit chip on a top surface of the first substrate portion and electrically connecting the circuit chip to a plurality of first ball pads positioned on a bottom surface of the first substrate portion; applying a molding resin to cover the first substrate portion and the integrated circuit chip; bending the second substrate portion so that the third substrate portion is positioned on a top surface of the molding resin, a top surface of the third substrate portion comprising a plurality of second ball pads; forming an upper ball grid package that includes a second integrated circuit positioned on a top substrate; forming balls on the plurality of ball pads on the bottom surface of the top substrate; and positioning the upper ball grid package on the lower ball grid package so that the balls on the bottom surface of the upper ball grid package are aligned with the top ball pads on the top surface of the third substrate portion of the lower ball grid package, wherein each of the plurality of first ball pads is electrically connected to a corresponding one of the plurality of second ball pads by a connection line.