Patent ID: 6306682
Filing Date: 2001-10-23
Classification: H01L

Abstract:
A method for fabricating a BGA IC package, comprising the steps of:(1) preparing a copper piece having a first surface coated with a first photoresist layer and a second surface coated with a second photoresist layer,(2) performing a selective-removal process on the second photoresist layer;(3) coating an electrically-conductive material over those areas over the second surface of the copper piece that are unmasked by the remaining part of the second photoresist layer to thereby form an electrically-conductive trace structure;(4) removing all the remaining parts of the first and second photoresist layers;(5) coating a first solder mask over the first surface of the copper piece and a second solder mask over the second surface of the copper piece;(6) defining a plurality of solder-ball openings in the second solder mask and an encapsulating-body opening in the first solder mask,(7) with the first solder mask serving as mask, removing the unmasked part of the copper piece through the encapsulating-body opening until reaching the electrically-conductive trace structure on the opposite side of the copper piece to thereby form an encapsulating-body cavity in the copper piece;(8) mounting at least one IC chip within the encapsulating-body cavity and over the electrically-conductive trace structure and the second solder mask;(9) electrically coupling the IC chip to corresponding points on the electrically-conductive trace structure;(10) forming an encapsulating body in the combined hollow space of the encapsulating-body cavity and the encapsulating-body opening;(11) implanting a plurality of electrically-conductive balls in the solder-ball openings; and(12) cutting away the remaining parts of the copper piece.